diff --git a/core/modules/action/tests/src/Functional/ConfigurationTest.php b/core/modules/action/tests/src/Functional/ConfigurationTest.php
index 8844cb0979b76e75f25404e1b6bf112aa76cd430..051ba5032b73485dcea706ab2fb9a5a767a82cd1 100644
--- a/core/modules/action/tests/src/Functional/ConfigurationTest.php
+++ b/core/modules/action/tests/src/Functional/ConfigurationTest.php
@@ -6,7 +6,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Tests complex actions configuration.
+ * Tests complex actions configuration by adding, editing, and deleting a
+ * complex action.
  *
  * @group action
  */
diff --git a/core/modules/block/tests/src/Functional/BlockHiddenRegionTest.php b/core/modules/block/tests/src/Functional/BlockHiddenRegionTest.php
index 7f5906be7d784cb931021574264bc83651eca49d..06cbe8b2370565086603d28e6dc80eeba1a357b0 100644
--- a/core/modules/block/tests/src/Functional/BlockHiddenRegionTest.php
+++ b/core/modules/block/tests/src/Functional/BlockHiddenRegionTest.php
@@ -5,7 +5,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Tests that blocks are not added to hidden regions on theme installation.
+ * Tests that a newly installed theme does not inherit blocks to its hidden
+ * regions.
  *
  * @group block
  */
diff --git a/core/modules/block/tests/src/Functional/BlockInvalidRegionTest.php b/core/modules/block/tests/src/Functional/BlockInvalidRegionTest.php
index 9a0052b07a2f383bb0082b2ddd26e2543dbf5e16..f11dc77fd3719b2549bc3247d48b6f1753a3ee87 100644
--- a/core/modules/block/tests/src/Functional/BlockInvalidRegionTest.php
+++ b/core/modules/block/tests/src/Functional/BlockInvalidRegionTest.php
@@ -6,7 +6,8 @@
 use Drupal\block\Entity\Block;
 
 /**
- * Tests that blocks assigned to invalid regions are disabled with a warning.
+ * Tests that an active block assigned to a non-existing region triggers the
+ * warning message and is disabled.
  *
  * @group block
  */
diff --git a/core/modules/block/tests/src/Functional/BlockLanguageTest.php b/core/modules/block/tests/src/Functional/BlockLanguageTest.php
index 95c2b3fa4df0c0da93429398b17d16d12383a5e0..7020fd5df9c0ad32a02daa3bf11ca7ab110a8614 100644
--- a/core/modules/block/tests/src/Functional/BlockLanguageTest.php
+++ b/core/modules/block/tests/src/Functional/BlockLanguageTest.php
@@ -6,7 +6,8 @@
 use Drupal\block\Entity\Block;
 
 /**
- * Tests per-language block configuration.
+ * Tests if a block can be configured to be only visible on a particular
+ * language.
  *
  * @group block
  */
diff --git a/core/modules/comment/tests/src/Functional/CommentTitleTest.php b/core/modules/comment/tests/src/Functional/CommentTitleTest.php
index 5f94a88e9a258f4c6374ca26bcfa3208192233e9..69d65cf4851e534ac903d69a05af1f57905a1c12 100644
--- a/core/modules/comment/tests/src/Functional/CommentTitleTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentTitleTest.php
@@ -3,7 +3,8 @@
 namespace Drupal\Tests\comment\Functional;
 
 /**
- * Tests that appropriate and accessible markup is created for comment titles.
+ * Tests to ensure that appropriate and accessible markup is created for comment
+ * titles.
  *
  * @group comment
  */
diff --git a/core/modules/comment/tests/src/Functional/CommentTokenReplaceTest.php b/core/modules/comment/tests/src/Functional/CommentTokenReplaceTest.php
index 40a6484ebb7fbac9f672c29e4bfd2e3f2917a7e4..4fffc6e042de53b6a8c61210c0af290d7d2f0dda 100644
--- a/core/modules/comment/tests/src/Functional/CommentTokenReplaceTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentTokenReplaceTest.php
@@ -13,7 +13,8 @@
 use Drupal\user\Entity\User;
 
 /**
- * Tests comment token replacement.
+ * Generates text using placeholders for dummy content to check comment token
+ * replacement.
  *
  * @group comment
  */
diff --git a/core/modules/comment/tests/src/Kernel/CommentDefaultFormatterCacheTagsTest.php b/core/modules/comment/tests/src/Kernel/CommentDefaultFormatterCacheTagsTest.php
index a0dd05c23a8376b5167257afca5472abfa5a2525..4df8d4cd51fc19560cef532071380a0f8e71378a 100644
--- a/core/modules/comment/tests/src/Kernel/CommentDefaultFormatterCacheTagsTest.php
+++ b/core/modules/comment/tests/src/Kernel/CommentDefaultFormatterCacheTagsTest.php
@@ -12,7 +12,8 @@
 use Drupal\entity_test\Entity\EntityTest;
 
 /**
- * Tests comment cache tag bubbling up when using the Comment list formatter.
+ * Tests the bubbling up of comment cache tags when using the Comment list
+ * formatter on an entity.
  *
  * @group comment
  */
diff --git a/core/modules/config/tests/src/Functional/ConfigInstallProfileOverrideTest.php b/core/modules/config/tests/src/Functional/ConfigInstallProfileOverrideTest.php
index 4a5ca18c7a2608c1ac8f93238de57c951c63086f..e022d5f126d3fd04d40ed94ae40a5f79e1f2de4f 100644
--- a/core/modules/config/tests/src/Functional/ConfigInstallProfileOverrideTest.php
+++ b/core/modules/config/tests/src/Functional/ConfigInstallProfileOverrideTest.php
@@ -12,10 +12,8 @@
 use Drupal\user\Entity\Role;
 
 /**
- * Tests that configuration objects are correct after various operations.
- *
- * The installation and removal of configuration objects in install, disable
- * and uninstall functionality is tested.
+ * Tests installation and removal of configuration objects in install, disable
+ * and uninstall functionality.
  *
  * @group config
  */
diff --git a/core/modules/config/tests/src/Functional/ConfigInstallWebTest.php b/core/modules/config/tests/src/Functional/ConfigInstallWebTest.php
index 314c3d50dbb4a3083b1e3e881bd8301264bb4010..fc27b7d9bd80323172b4a5fc0fa46dedca86503f 100644
--- a/core/modules/config/tests/src/Functional/ConfigInstallWebTest.php
+++ b/core/modules/config/tests/src/Functional/ConfigInstallWebTest.php
@@ -11,10 +11,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Tests configuration objects before and after module install and uninstall.
- *
- * The installation and removal of configuration objects in install, disable
- * and uninstall functionality is tested.
+ * Tests installation and removal of configuration objects in install, disable
+ * and uninstall functionality.
  *
  * @group config
  */
diff --git a/core/modules/contextual/tests/src/Functional/ContextualDynamicContextTest.php b/core/modules/contextual/tests/src/Functional/ContextualDynamicContextTest.php
index b04f716a56b6d6d6190aa066089e694c092a9231..f1fb389b0d8e34fd6be488c65ecc5fabcbb41b68 100644
--- a/core/modules/contextual/tests/src/Functional/ContextualDynamicContextTest.php
+++ b/core/modules/contextual/tests/src/Functional/ContextualDynamicContextTest.php
@@ -10,7 +10,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Tests contextual link display on the front page based on permissions.
+ * Tests if contextual links are showing on the front page depending on
+ * permissions.
  *
  * @group contextual
  */
diff --git a/core/modules/dblog/tests/src/Functional/DbLogTest.php b/core/modules/dblog/tests/src/Functional/DbLogTest.php
index 9f16b406fb539ea1e424d9d5ada63a7b8256ae08..173c17795aea08bb7c3b8c8d50cf2be022c2d1eb 100644
--- a/core/modules/dblog/tests/src/Functional/DbLogTest.php
+++ b/core/modules/dblog/tests/src/Functional/DbLogTest.php
@@ -14,7 +14,8 @@
 use Drupal\Tests\system\Functional\Menu\AssertBreadcrumbTrait;
 
 /**
- * Verifies log entries and user access based on permissions.
+ * Generate events and verify dblog entries; verify user access to log reports
+ * based on permissions.
  *
  * @group dblog
  */
diff --git a/core/modules/dblog/tests/src/Functional/DbLogViewsTest.php b/core/modules/dblog/tests/src/Functional/DbLogViewsTest.php
index d6794a01c49b90d7f8fe233ffa560955d7d39421..284b3bab9b9a314d5e13086132b80ebfed3415e3 100644
--- a/core/modules/dblog/tests/src/Functional/DbLogViewsTest.php
+++ b/core/modules/dblog/tests/src/Functional/DbLogViewsTest.php
@@ -5,7 +5,8 @@
 use Drupal\views\Views;
 
 /**
- * Verifies user access to log reports based on permissions.
+ * Generate events and verify dblog entries; verify user access to log reports
+ * based on permissions. Using the dblog UI generated by a View.
  *
  * @see Drupal\dblog\Tests\DbLogTest
  *
diff --git a/core/modules/field/tests/src/Functional/FieldImportDeleteUninstallUiTest.php b/core/modules/field/tests/src/Functional/FieldImportDeleteUninstallUiTest.php
index 0ab8be68cac6dd91b4f98d9cdbdbb75213d60a7a..b7dbac9c98c5cd5cd36bdbab89994de6be80fb6d 100644
--- a/core/modules/field/tests/src/Functional/FieldImportDeleteUninstallUiTest.php
+++ b/core/modules/field/tests/src/Functional/FieldImportDeleteUninstallUiTest.php
@@ -7,7 +7,8 @@
 use Drupal\field\Entity\FieldStorageConfig;
 
 /**
- * Tests deleting field storage when a module in uninstalled through the UI.
+ * Delete field storages and fields during config synchronization and uninstall
+ * module that provides the field type through the UI.
  *
  * @group field
  * @see \Drupal\field\ConfigImporterFieldPurger
diff --git a/core/modules/field/tests/src/Kernel/FieldDataCountTest.php b/core/modules/field/tests/src/Kernel/FieldDataCountTest.php
index f521d6236bab866f7f424245f388806abf95e271..4b067276c3dab48167e444b9b223853f2d916aeb 100644
--- a/core/modules/field/tests/src/Kernel/FieldDataCountTest.php
+++ b/core/modules/field/tests/src/Kernel/FieldDataCountTest.php
@@ -10,7 +10,8 @@
 use Drupal\field\Entity\FieldStorageConfig;
 
 /**
- * Tests the count of field data records.
+ * Tests counting field data records and the hasData() method on
+ * FieldStorageConfig entity.
  *
  * @group field
  * @see \Drupal\Core\Entity\FieldableEntityStorageInterface::countFieldData()
diff --git a/core/modules/field/tests/src/Kernel/FieldImportDeleteUninstallTest.php b/core/modules/field/tests/src/Kernel/FieldImportDeleteUninstallTest.php
index 9e2e27bac4cc59db5e05ec7affaca1c9bfe30409..48e553cd32c48dc821bffbcb57cde7f787d5de59 100644
--- a/core/modules/field/tests/src/Kernel/FieldImportDeleteUninstallTest.php
+++ b/core/modules/field/tests/src/Kernel/FieldImportDeleteUninstallTest.php
@@ -7,7 +7,8 @@
 use Drupal\field\Entity\FieldStorageConfig;
 
 /**
- * Tests field storages and fields deletion during config synchronization.
+ * Delete field storages and fields during config synchronization and uninstall
+ * module that provides the field type.
  *
  * @group field
  * @see \Drupal\field\ConfigImporterFieldPurger
diff --git a/core/modules/file/tests/src/Functional/FileFieldValidateTest.php b/core/modules/file/tests/src/Functional/FileFieldValidateTest.php
index 292d24abc07c123bcb4c22ab67056011df75263e..005bc1badbba81b315cb5b0c504373c7f3a6ad60 100644
--- a/core/modules/file/tests/src/Functional/FileFieldValidateTest.php
+++ b/core/modules/file/tests/src/Functional/FileFieldValidateTest.php
@@ -8,10 +8,8 @@
 use Drupal\file\Entity\File;
 
 /**
- * Tests file field validation functions.
- *
- * Values validated include the file type, max file size, max size per node,
- * and whether the field is required.
+ * Tests validation functions such as file type, max file size, max size per
+ * node, and required.
  *
  * @group file
  */
diff --git a/core/modules/file/tests/src/Functional/FileManagedTestBase.php b/core/modules/file/tests/src/Functional/FileManagedTestBase.php
index 61a0f5b76ba7b513ad99e9d5199dc1433dead111..689dd3b7b1ecf2aae50ba7dd3f12e04ed2129395 100644
--- a/core/modules/file/tests/src/Functional/FileManagedTestBase.php
+++ b/core/modules/file/tests/src/Functional/FileManagedTestBase.php
@@ -8,7 +8,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Provides a base class for testing files with the file_test module.
+ * Base class for file tests that use the file_test module to test uploads and
+ * hooks.
  */
 abstract class FileManagedTestBase extends BrowserTestBase {
 
diff --git a/core/modules/file/tests/src/Functional/FileTokenReplaceTest.php b/core/modules/file/tests/src/Functional/FileTokenReplaceTest.php
index 86fe0ed5d1768bff69d5d11277133dbce2965c74..041b0fe20ed37bdc757859da1c55832dc1bdca7b 100644
--- a/core/modules/file/tests/src/Functional/FileTokenReplaceTest.php
+++ b/core/modules/file/tests/src/Functional/FileTokenReplaceTest.php
@@ -8,7 +8,8 @@
 use Drupal\file\Entity\File;
 
 /**
- * Tests file token replacement.
+ * Generates text using placeholders for dummy content to check file token
+ * replacement.
  *
  * @group file
  */
diff --git a/core/modules/file/tests/src/FunctionalJavascript/FileFieldValidateTest.php b/core/modules/file/tests/src/FunctionalJavascript/FileFieldValidateTest.php
index 1d50b3bfd7a49f3dc8c9ea61d51d0f03a98d25e1..6c667ecd126186bd09d8d61ce4ab72ee9ae53ac5 100644
--- a/core/modules/file/tests/src/FunctionalJavascript/FileFieldValidateTest.php
+++ b/core/modules/file/tests/src/FunctionalJavascript/FileFieldValidateTest.php
@@ -7,10 +7,8 @@
 use Drupal\Tests\TestFileCreationTrait;
 
 /**
- * Tests file field validation functions.
- *
- * Values validated include the file type, max file size, max size per node,
- * and whether the field is required.
+ * Tests validation functions such as file type, max file size, max size per
+ * node, and required.
  *
  * @group file
  */
diff --git a/core/modules/file/tests/src/Kernel/FileManagedUnitTestBase.php b/core/modules/file/tests/src/Kernel/FileManagedUnitTestBase.php
index d2ad5dab969155545e92a703a4488cc10b723e59..4441fd333f91438bf6e4673a906bc1b65c798847 100644
--- a/core/modules/file/tests/src/Kernel/FileManagedUnitTestBase.php
+++ b/core/modules/file/tests/src/Kernel/FileManagedUnitTestBase.php
@@ -9,7 +9,8 @@
 use Drupal\user\Entity\User;
 
 /**
- * Provides a base class for testing file uploads and hook invocations.
+ * Base class for file unit tests that use the file_test module to test uploads and
+ * hooks.
  */
 abstract class FileManagedUnitTestBase extends KernelTestBase {
 
diff --git a/core/modules/filter/tests/src/Functional/FilterSecurityTest.php b/core/modules/filter/tests/src/Functional/FilterSecurityTest.php
index ebe5a78774785592ba0222ced545cf0175a41ec2..0e200f16c6f7ad42a4be0de5692a894b30a98eb4 100644
--- a/core/modules/filter/tests/src/Functional/FilterSecurityTest.php
+++ b/core/modules/filter/tests/src/Functional/FilterSecurityTest.php
@@ -8,7 +8,9 @@
 use Drupal\user\RoleInterface;
 
 /**
- * Tests HTML filtering with missing or skipped filters or text formats.
+ * Tests the behavior of check_markup() when a filter or text format vanishes,
+ * or when check_markup() is called in such a way that it is instructed to skip
+ * all filters of the "FilterInterface::TYPE_HTML_RESTRICTOR" type.
  *
  * @group filter
  */
diff --git a/core/modules/language/tests/src/Functional/LanguageListModuleInstallTest.php b/core/modules/language/tests/src/Functional/LanguageListModuleInstallTest.php
index 2b3fcf49e3ab0a1f02bd76bc72639b747ed8bcf6..9a7e9ddabec2ff217a43ada4972ebf2abfb2ab86 100644
--- a/core/modules/language/tests/src/Functional/LanguageListModuleInstallTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageListModuleInstallTest.php
@@ -5,7 +5,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Tests that the language list is not empty when language is installed.
+ * Tests enabling Language if a module exists that calls
+ * LanguageManager::getLanguages() during installation.
  *
  * @group language
  */
diff --git a/core/modules/language/tests/src/Kernel/Condition/LanguageConditionTest.php b/core/modules/language/tests/src/Kernel/Condition/LanguageConditionTest.php
index 2175a3a9ee0811a6ad3a58856de513daa2e3ee77..d664fd5b435a85bf78aa9087eca2e78a46e18795 100644
--- a/core/modules/language/tests/src/Kernel/Condition/LanguageConditionTest.php
+++ b/core/modules/language/tests/src/Kernel/Condition/LanguageConditionTest.php
@@ -6,7 +6,8 @@
 use Drupal\KernelTests\KernelTestBase;
 
 /**
- * Tests the language condition plugin.
+ * Tests that the language condition, provided by the language module, is
+ * working properly.
  *
  * @group language
  */
diff --git a/core/modules/language/tests/src/Kernel/LanguageDependencyInjectionTest.php b/core/modules/language/tests/src/Kernel/LanguageDependencyInjectionTest.php
index 954614d3a5d913e3691c929903d26ad9fe11a55f..dff6af4c2b3799415f8510b64d9390cd157d4a9e 100644
--- a/core/modules/language/tests/src/Kernel/LanguageDependencyInjectionTest.php
+++ b/core/modules/language/tests/src/Kernel/LanguageDependencyInjectionTest.php
@@ -6,7 +6,8 @@
 use Drupal\language\Exception\DeleteDefaultLanguageException;
 
 /**
- * Tests that a language object can be injected.
+ * Compares the default language from $GLOBALS against the dependency injected
+ * language object.
  *
  * @group language
  */
diff --git a/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageContentSettingsTest.php b/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageContentSettingsTest.php
index 9a3d46335c342d9568e76d35481ffba5c7eca788..394e18e591c6df0beed0ce9e1f62d03b029921e9 100644
--- a/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageContentSettingsTest.php
+++ b/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageContentSettingsTest.php
@@ -6,9 +6,7 @@
 use Drupal\Tests\migrate_drupal\Kernel\d6\MigrateDrupal6TestBase;
 
 /**
- * Tests the migration of language-related settings.
- *
- * Settings tested include language content setting variables,
+ * Tests migration of language content setting variables,
  * language_content_type_$type, i18n_node_options_* and i18n_lock_node_*.
  *
  * @group migrate_drupal_6
diff --git a/core/modules/language/tests/src/Kernel/Migrate/d7/MigrateLanguageContentSettingsTest.php b/core/modules/language/tests/src/Kernel/Migrate/d7/MigrateLanguageContentSettingsTest.php
index ed65ee448ad69be4003dc2be6c5ae187fc3e1e7c..b86378c2d571b0102fe064aca646caee069c5512 100644
--- a/core/modules/language/tests/src/Kernel/Migrate/d7/MigrateLanguageContentSettingsTest.php
+++ b/core/modules/language/tests/src/Kernel/Migrate/d7/MigrateLanguageContentSettingsTest.php
@@ -6,9 +6,7 @@
 use Drupal\Tests\migrate_drupal\Kernel\d7\MigrateDrupal7TestBase;
 
 /**
- * Tests the migration of language-related settings.
- *
- * Settings tested include the language content setting variables,
+ * Tests migration of language content setting variables,
  * language_content_type_$type, i18n_node_options_* and i18n_lock_node_*.
  *
  * @group migrate_drupal_7
diff --git a/core/modules/layout_builder/tests/modules/layout_builder_element_test/src/EventSubscriber/TestPrepareLayout.php b/core/modules/layout_builder/tests/modules/layout_builder_element_test/src/EventSubscriber/TestPrepareLayout.php
index 7162b96715365c94abbeb1be6353bd3d34938252..0d9c1afd5026ce0149be9663437b2fc3289e5cdc 100644
--- a/core/modules/layout_builder/tests/modules/layout_builder_element_test/src/EventSubscriber/TestPrepareLayout.php
+++ b/core/modules/layout_builder/tests/modules/layout_builder_element_test/src/EventSubscriber/TestPrepareLayout.php
@@ -12,7 +12,8 @@
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
 /**
- * Provides an event subscriber for testing section storage alteration.
+ * An event subscriber to test altering section storage via the
+ * \Drupal\layout_builder\Event\PrepareLayoutEvent.
  *
  * @see \Drupal\layout_builder\Event\PrepareLayoutEvent
  * @see \Drupal\layout_builder\Element\LayoutBuilder::prepareLayout()
diff --git a/core/modules/locale/tests/src/Functional/LocaleContentTest.php b/core/modules/locale/tests/src/Functional/LocaleContentTest.php
index 2a06080046d0d9b54b7e1353811ac707a430102a..ce06b9d2a3f12e55eee70a7e3e7430f240ed8231 100644
--- a/core/modules/locale/tests/src/Functional/LocaleContentTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleContentTest.php
@@ -7,7 +7,8 @@
 use Drupal\node\NodeInterface;
 
 /**
- * Tests multilingual support for content types and individual nodes.
+ * Tests you can enable multilingual support on content types and configure a
+ * language for a node.
  *
  * @group locale
  */
diff --git a/core/modules/locale/tests/src/Functional/LocaleTranslationUiTest.php b/core/modules/locale/tests/src/Functional/LocaleTranslationUiTest.php
index cbca227ad7fae3acd2da6be8b2cfb58d05e07f13..cdedb12cd35b163dae131f77411c16178bdc49fc 100644
--- a/core/modules/locale/tests/src/Functional/LocaleTranslationUiTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleTranslationUiTest.php
@@ -9,7 +9,8 @@
 use Drupal\Core\Language\LanguageInterface;
 
 /**
- * Tests the validation of translation strings and search results.
+ * Adds a new locale and translates its name. Checks the validation of
+ * translation strings and search results.
  *
  * @group locale
  */
diff --git a/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentCacheabilityBubblingTest.php b/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentCacheabilityBubblingTest.php
index bc1288972936ef9118ffbc0292813fb208e79852..27b49b27ee8989a8bb81c727a6f218777a9cec6e 100644
--- a/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentCacheabilityBubblingTest.php
+++ b/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentCacheabilityBubblingTest.php
@@ -15,9 +15,8 @@
 use Symfony\Component\Routing\Route;
 
 /**
- * Ensures that rendered menu links bubble the necessary bubbleable metadata.
- *
- * This for outbound path/route processing.
+ * Ensures that rendered menu links bubble the necessary bubbleable metadata
+ * for outbound path/route processing.
  *
  * @group menu_link_content
  */
diff --git a/core/modules/menu_ui/tests/src/Functional/MenuUiTest.php b/core/modules/menu_ui/tests/src/Functional/MenuUiTest.php
index f6000557d3c2ef040a01dcb168644ef9cfee6b51..96411404b56276f4ce7042d09df8dae01c769b4c 100644
--- a/core/modules/menu_ui/tests/src/Functional/MenuUiTest.php
+++ b/core/modules/menu_ui/tests/src/Functional/MenuUiTest.php
@@ -15,10 +15,8 @@
 use Drupal\Tests\menu_ui\Traits\MenuUiTrait;
 
 /**
- * Tests the menu UI.
- *
- * This test adds a custom menu, adds menu links to the custom menu and the
- * Tools menu, checks their data, and deletes them using the UI.
+ * Add a custom menu, add menu links to the custom menu and Tools menu, check
+ * their data, and delete them using the UI.
  *
  * @group menu_ui
  */
diff --git a/core/modules/migrate/tests/src/Unit/MigrateSourceTest.php b/core/modules/migrate/tests/src/Unit/MigrateSourceTest.php
index 2afddd72d4e4a1ac47060e73a6ef61e2fb5c027d..8f5d2e627d157143a05e8e039bcec1efe4c4e622 100644
--- a/core/modules/migrate/tests/src/Unit/MigrateSourceTest.php
+++ b/core/modules/migrate/tests/src/Unit/MigrateSourceTest.php
@@ -500,10 +500,8 @@ protected function initializeIterator() {
 }
 
 /**
- * Defines a stubbed source plugin with a generator as iterator.
- *
- * This stub overwrites the $skipCount, $cacheCounts, and $trackChanges
- * properties.
+ * Stubbed source plugin with a generator as iterator. Also it overwrites the
+ * $skipCount, $cacheCounts and $trackChanges properties.
  */
 class StubSourceGeneratorPlugin extends StubSourcePlugin {
 
diff --git a/core/modules/node/tests/src/Functional/NodeAccessRebuildNodeGrantsTest.php b/core/modules/node/tests/src/Functional/NodeAccessRebuildNodeGrantsTest.php
index 50e5e62eb1192420e2487534d606ac16ee1e8cf4..31fee1ccd26fde0be94b2f4cd31267507e41c203 100644
--- a/core/modules/node/tests/src/Functional/NodeAccessRebuildNodeGrantsTest.php
+++ b/core/modules/node/tests/src/Functional/NodeAccessRebuildNodeGrantsTest.php
@@ -5,7 +5,8 @@
 use Drupal\node\Entity\NodeType;
 
 /**
- * Tests node access rebuild functions with multiple node access modules.
+ * Ensures that node access rebuild functions work correctly even
+ * when other modules implements hook_node_grants().
  *
  * @group node
  */
diff --git a/core/modules/node/tests/src/Functional/NodePostSettingsTest.php b/core/modules/node/tests/src/Functional/NodePostSettingsTest.php
index ba22129b36a93ce242ef37bd216bd622f20f8eca..6610cc67e69b413e8b14a855d43e2ea241e5de19 100644
--- a/core/modules/node/tests/src/Functional/NodePostSettingsTest.php
+++ b/core/modules/node/tests/src/Functional/NodePostSettingsTest.php
@@ -3,7 +3,8 @@
 namespace Drupal\Tests\node\Functional;
 
 /**
- * Tests the node setting for displaying author and date information.
+ * Tests that the post information (submitted by Username on date) text displays
+ * appropriately.
  *
  * @group node
  */
diff --git a/core/modules/node/tests/src/Functional/NodeRevisionsAllTest.php b/core/modules/node/tests/src/Functional/NodeRevisionsAllTest.php
index b496cf6beb63ffbaf16420ec51a6dd92255554b9..a9687f63e7b0080f2d717dfd77ba49c45a073d01 100644
--- a/core/modules/node/tests/src/Functional/NodeRevisionsAllTest.php
+++ b/core/modules/node/tests/src/Functional/NodeRevisionsAllTest.php
@@ -6,7 +6,8 @@
 use Drupal\node\NodeInterface;
 
 /**
- * Tests global node CRUD operation permissions.
+ * Create a node with revisions and test viewing, saving, reverting, and
+ * deleting revisions for user with access to all.
  *
  * @group node
  */
diff --git a/core/modules/node/tests/src/Functional/NodeRevisionsTest.php b/core/modules/node/tests/src/Functional/NodeRevisionsTest.php
index d9df596421a628888a797b9897f21ede9e552b18..d6ce481ad1bfb6597d490eb44a9596d817429cec 100644
--- a/core/modules/node/tests/src/Functional/NodeRevisionsTest.php
+++ b/core/modules/node/tests/src/Functional/NodeRevisionsTest.php
@@ -11,7 +11,8 @@
 use Drupal\node\NodeInterface;
 
 /**
- * Tests per-content-type node CRUD operation permissions.
+ * Create a node with revisions and test viewing, saving, reverting, and
+ * deleting revisions for users with access for this content type.
  *
  * @group node
  */
diff --git a/core/modules/node/tests/src/Functional/NodeTitleXSSTest.php b/core/modules/node/tests/src/Functional/NodeTitleXSSTest.php
index 87d36e2c490f2b1f143767e26339a68eb777532a..dcbac6a1ef0a7cb64140b3b807e528dc29dfdc73 100644
--- a/core/modules/node/tests/src/Functional/NodeTitleXSSTest.php
+++ b/core/modules/node/tests/src/Functional/NodeTitleXSSTest.php
@@ -5,7 +5,8 @@
 use Drupal\Component\Utility\Html;
 
 /**
- * Tests that dangerous tags in the node title are escaped.
+ * Create a node with dangerous tags in its title and test that they are
+ * escaped.
  *
  * @group node
  */
diff --git a/core/modules/node/tests/src/Kernel/NodeAccessLanguageAwareCombinationTest.php b/core/modules/node/tests/src/Kernel/NodeAccessLanguageAwareCombinationTest.php
index a3202cfc5b85cda85740cb61b2ebfc7e84be9191..f8a2e5f0e2beb089f1a993272ce483ea5344907e 100644
--- a/core/modules/node/tests/src/Kernel/NodeAccessLanguageAwareCombinationTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeAccessLanguageAwareCombinationTest.php
@@ -11,7 +11,8 @@
 use Drupal\field\Entity\FieldStorageConfig;
 
 /**
- * Tests node access with multiple languages and two node access modules.
+ * Tests node access functionality with multiple languages and two node access
+ * modules.
  *
  * @group node
  */
diff --git a/core/modules/node/tests/src/Kernel/NodeAccessLanguageAwareTest.php b/core/modules/node/tests/src/Kernel/NodeAccessLanguageAwareTest.php
index c4afd4d319a629a98732694a15e7870500f1d9c0..c3fc89d2f28a88e7caf522a9ebbbb8de2b70312f 100644
--- a/core/modules/node/tests/src/Kernel/NodeAccessLanguageAwareTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeAccessLanguageAwareTest.php
@@ -10,7 +10,8 @@
 use Drupal\field\Entity\FieldStorageConfig;
 
 /**
- * Tests multilingual node access with a language-aware module.
+ * Tests node_access and select queries with node_access tag functionality with
+ * multiple languages with node_access_test_language which is language-aware.
  *
  * @group node
  */
diff --git a/core/modules/node/tests/src/Kernel/NodeAccessLanguageTest.php b/core/modules/node/tests/src/Kernel/NodeAccessLanguageTest.php
index 29a2e96a58e805d99a10fc6d789d0b4f53e1a39b..7e9f8873006a2134828d3628a2f7a8f5455cfe23 100644
--- a/core/modules/node/tests/src/Kernel/NodeAccessLanguageTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeAccessLanguageTest.php
@@ -9,7 +9,8 @@
 use Drupal\user\Entity\User;
 
 /**
- * Tests multilingual node access with a module that is not language-aware.
+ * Tests node_access and select queries with node_access tag functionality with
+ * multiple languages with a test node access module that is not language-aware.
  *
  * @group node
  */
diff --git a/core/modules/node/tests/src/Kernel/NodeTokenReplaceTest.php b/core/modules/node/tests/src/Kernel/NodeTokenReplaceTest.php
index a18faf871e8cf242568b4f470d4baf7bdfc82ddf..4f10dce724425bee58fd232390f836b0cdcc6a15 100644
--- a/core/modules/node/tests/src/Kernel/NodeTokenReplaceTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeTokenReplaceTest.php
@@ -9,7 +9,8 @@
 use Drupal\Tests\system\Kernel\Token\TokenReplaceKernelTestBase;
 
 /**
- * Tests node token replacement.
+ * Generates text using placeholders for dummy content to check node token
+ * replacement.
  *
  * @group node
  */
diff --git a/core/modules/path/tests/src/Functional/PathAliasTest.php b/core/modules/path/tests/src/Functional/PathAliasTest.php
index 79523459afa1f957344e8e6d8c1f053ea7f395b6..b55a8a4b6b4588005dfefc6064feac9ef186072b 100644
--- a/core/modules/path/tests/src/Functional/PathAliasTest.php
+++ b/core/modules/path/tests/src/Functional/PathAliasTest.php
@@ -7,7 +7,8 @@
 use Drupal\Core\Url;
 
 /**
- * Tests modifying path aliases from the UI.
+ * Add, edit, delete, and change alias and verify its consistency in the
+ * database.
  *
  * @group path
  */
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php
index 6fd4da3e873b1dea6c7e19f567598a9e2ea7dc25..49db1df5de80f8a3c46125ebf7a214db4ee0aac1 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php
@@ -24,8 +24,6 @@
 use Psr\Http\Message\ResponseInterface;
 
 /**
- * Defines a base class for testing all entity resources.
- *
  * Even though there is the generic EntityResource, it's necessary for every
  * entity type to have its own test, because they each have different fields,
  * validation constraints, et cetera. It's not because the generic case works,
diff --git a/core/modules/serialization/tests/src/Unit/Normalizer/DateTimeIso8601NormalizerTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/DateTimeIso8601NormalizerTest.php
index 98ca2ac7d0cd172262a5951a8d18041456a6571a..322223ec8ecf90feac98e54bb7ea58a4e86f1e33 100644
--- a/core/modules/serialization/tests/src/Unit/Normalizer/DateTimeIso8601NormalizerTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/DateTimeIso8601NormalizerTest.php
@@ -256,8 +256,6 @@ public function testDenormalizeNoTargetInstanceOrFieldDefinitionException() {
 }
 
 /**
- * Provides a test class for testing DrupalDateTime.
- *
  * Note: Prophecy does not support magic methods. By subclassing and specifying
  * an explicit method, Prophecy works.
  * @see https://github.com/phpspec/prophecy/issues/338
diff --git a/core/modules/serialization/tests/src/Unit/Normalizer/DateTimeNormalizerTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/DateTimeNormalizerTest.php
index 0d270d5e89f4f0d2d1a9ae8049a8742fdee186da..fe503e01a2a20e15922aef9437aa1a1a51d88ae6 100644
--- a/core/modules/serialization/tests/src/Unit/Normalizer/DateTimeNormalizerTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/DateTimeNormalizerTest.php
@@ -178,8 +178,6 @@ public function testDenormalizeException() {
 
 
 /**
- * Provides a test class for testing DrupalDateTime.
- *
  * Note: Prophecy does not support magic methods. By subclassing and specifying
  * an explicit method, Prophecy works.
  * @see https://github.com/phpspec/prophecy/issues/338
diff --git a/core/modules/serialization/tests/src/Unit/Normalizer/TimestampNormalizerTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/TimestampNormalizerTest.php
index 750d9d2997af021362636cc1f0f646865cfa73f4..b1851ab9e1d37f5d4bb5b2893e3d315200484cb3 100644
--- a/core/modules/serialization/tests/src/Unit/Normalizer/TimestampNormalizerTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/TimestampNormalizerTest.php
@@ -133,8 +133,6 @@ public function testDenormalizeException() {
 }
 
 /**
- * Provides a test class for testing DrupalDateTime.
- *
  * Note: Prophecy does not support magic methods. By subclassing and specifying
  * an explicit method, Prophecy works.
  * @see https://github.com/phpspec/prophecy/issues/338
diff --git a/core/modules/statistics/tests/src/Functional/StatisticsTokenReplaceTest.php b/core/modules/statistics/tests/src/Functional/StatisticsTokenReplaceTest.php
index 4b81e983f86af3e4e720e34d141b41e1f22e178b..879f16cc90bc6c7ee5d96dc548ef7ae9a7b96474 100644
--- a/core/modules/statistics/tests/src/Functional/StatisticsTokenReplaceTest.php
+++ b/core/modules/statistics/tests/src/Functional/StatisticsTokenReplaceTest.php
@@ -5,7 +5,8 @@
 use Drupal\Component\Render\FormattableMarkup;
 
 /**
- * Tests statistics token replacement.
+ * Generates text using placeholders for dummy content to check statistics token
+ * replacement.
  *
  * @group statistics
  */
diff --git a/core/modules/system/tests/modules/ajax_forms_test/src/Form/AjaxFormsTestAjaxElementsForm.php b/core/modules/system/tests/modules/ajax_forms_test/src/Form/AjaxFormsTestAjaxElementsForm.php
index 2e774f31fc2a724ebb60ade98acd0e5333385e89..41a9b6d92ab0a4bc447f1a0e4b4ad5d1c2af036c 100644
--- a/core/modules/system/tests/modules/ajax_forms_test/src/Form/AjaxFormsTestAjaxElementsForm.php
+++ b/core/modules/system/tests/modules/ajax_forms_test/src/Form/AjaxFormsTestAjaxElementsForm.php
@@ -7,7 +7,8 @@
 use Drupal\Core\Form\FormStateInterface;
 
 /**
- * Builds a form where each Form API element triggers a simple Ajax callback.
+ * Form builder: Builds a form that has each FAPI elements triggering a simple
+ * Ajax callback.
  *
  * @internal
  */
diff --git a/core/modules/system/tests/modules/module_install_class_loader_test1/src/EventSubscriber.php b/core/modules/system/tests/modules/module_install_class_loader_test1/src/EventSubscriber.php
index 5b467532bc407c1753469219a507a2ee85e44f56..e9e851799f4d0a53e2af7d18a472d5c814e0c53d 100644
--- a/core/modules/system/tests/modules/module_install_class_loader_test1/src/EventSubscriber.php
+++ b/core/modules/system/tests/modules/module_install_class_loader_test1/src/EventSubscriber.php
@@ -5,10 +5,8 @@
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
 /**
- * Defines an event subscriber that conditionally unsets the event list.
- *
- * @see Drupal\module_install_class_loader_test2\EventSubscriber
- * @see Drupal\Tests\system\Functional\Module\ClassLoaderTest::testMultipleModules()
+ * An event subscriber that does different things depending on whether classes
+ * exist.
  */
 class EventSubscriber implements EventSubscriberInterface {
 
diff --git a/core/modules/system/tests/modules/plugin_test/src/Plugin/plugin_test/mock_block/TypedDataStringBlock.php b/core/modules/system/tests/modules/plugin_test/src/Plugin/plugin_test/mock_block/TypedDataStringBlock.php
index 8ddf230930a844a3154a53ea335209fca32d0fad..5658cbf4240a00dce3ff08aa03ddad399cb764c0 100644
--- a/core/modules/system/tests/modules/plugin_test/src/Plugin/plugin_test/mock_block/TypedDataStringBlock.php
+++ b/core/modules/system/tests/modules/plugin_test/src/Plugin/plugin_test/mock_block/TypedDataStringBlock.php
@@ -7,10 +7,10 @@
 use Drupal\Core\Plugin\PluginBase;
 
 /**
- * Implements a String TypedData contextual block plugin.
+ * Implementation of a String TypedData contextual block plugin used by Plugin
+ * API context test.
  *
  * @see \Drupal\plugin_test\Plugin\MockBlockManager
- * @see \Drupal\KernelTests\Core\Plugin\PluginTestBase
  */
 class TypedDataStringBlock extends PluginBase implements ContextAwarePluginInterface {
 
diff --git a/core/modules/system/tests/src/Functional/Entity/EntityRevisionsTest.php b/core/modules/system/tests/src/Functional/Entity/EntityRevisionsTest.php
index 099ae3767674f86ba4b273833e92b92cf11031a8..dc355f05a8f862f46aeb06877aa0bc804c333e4d 100644
--- a/core/modules/system/tests/src/Functional/Entity/EntityRevisionsTest.php
+++ b/core/modules/system/tests/src/Functional/Entity/EntityRevisionsTest.php
@@ -10,7 +10,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Tests modifying an entity with revisions.
+ * Create a entity with revisions and test viewing, saving, reverting, and
+ * deleting revisions.
  *
  * @group Entity
  */
diff --git a/core/modules/system/tests/src/Functional/FileTransfer/FileTransferTest.php b/core/modules/system/tests/src/Functional/FileTransfer/FileTransferTest.php
index 9ddd26d9bc25f792ffff4dd46a3394e4f1e41c11..7d6bd2c9d44dc221c55ce4fae3db0fd14b6ced0b 100644
--- a/core/modules/system/tests/src/Functional/FileTransfer/FileTransferTest.php
+++ b/core/modules/system/tests/src/Functional/FileTransfer/FileTransferTest.php
@@ -7,7 +7,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Tests recursive file copy operations with the file transfer jail.
+ * Tests that the jail is respected and that protocols using recursive file move
+ * operations work.
  *
  * @group FileTransfer
  */
diff --git a/core/modules/system/tests/src/Functional/Form/CheckboxTest.php b/core/modules/system/tests/src/Functional/Form/CheckboxTest.php
index ed11505859b646fef2f623344146025621e83f2d..d5aebdb7f482872937c25395386a841cc01c5264 100644
--- a/core/modules/system/tests/src/Functional/Form/CheckboxTest.php
+++ b/core/modules/system/tests/src/Functional/Form/CheckboxTest.php
@@ -6,9 +6,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Tests the form API checkbox element.
- *
- * Various combinations of #default_value and #return_value are used.
+ * Tests form API checkbox handling of various combinations of #default_value
+ * and #return_value.
  *
  * @group Form
  */
diff --git a/core/modules/system/tests/src/Functional/Form/LanguageSelectElementTest.php b/core/modules/system/tests/src/Functional/Form/LanguageSelectElementTest.php
index 26fe1df96ad947109da7095f575ad365e1b91cbe..6622ce607c6cbc4726cbc197fbe3ad48260aff7d 100644
--- a/core/modules/system/tests/src/Functional/Form/LanguageSelectElementTest.php
+++ b/core/modules/system/tests/src/Functional/Form/LanguageSelectElementTest.php
@@ -8,7 +8,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Tests the language selection form element.
+ * Tests that the language select form element prints and submits the right
+ * options.
  *
  * @group Form
  */
diff --git a/core/modules/system/tests/src/Functional/Form/StateValuesCleanAdvancedTest.php b/core/modules/system/tests/src/Functional/Form/StateValuesCleanAdvancedTest.php
index 90e24029f2efff6bd96fea2f471688c2e3ae0989..b6aea0ead6942f00dd989791941392b039928349 100644
--- a/core/modules/system/tests/src/Functional/Form/StateValuesCleanAdvancedTest.php
+++ b/core/modules/system/tests/src/Functional/Form/StateValuesCleanAdvancedTest.php
@@ -6,7 +6,9 @@
 use Drupal\Tests\TestFileCreationTrait;
 
 /**
- * Tests the removal of internal Form API elements from submitted form values.
+ * Tests proper removal of submitted form values using
+ * \Drupal\Core\Form\FormState::cleanValues() when having forms with elements
+ * containing buttons like "managed_file".
  *
  * @group Form
  */
diff --git a/core/modules/system/tests/src/Functional/Form/StateValuesCleanTest.php b/core/modules/system/tests/src/Functional/Form/StateValuesCleanTest.php
index 4a2fc2a6a09d0396ff35cdd971d0fd8b6878cf00..473f98ee5ffce34dbaa347341155a8ebe6e3cdc0 100644
--- a/core/modules/system/tests/src/Functional/Form/StateValuesCleanTest.php
+++ b/core/modules/system/tests/src/Functional/Form/StateValuesCleanTest.php
@@ -7,9 +7,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Tests the proper removal of submitted form values.
- *
- * @see \Drupal\Core\Form\FormState::cleanValues()
+ * Tests proper removal of submitted form values using
+ * \Drupal\Core\Form\FormState::cleanValues().
  *
  * @group Form
  */
diff --git a/core/modules/system/tests/src/Functional/Form/StorageTest.php b/core/modules/system/tests/src/Functional/Form/StorageTest.php
index 9db4723caa4d151395cce60675c2b5dbb9b4217b..385ca20392a84a324da3f345cee70bb678ac28cd 100644
--- a/core/modules/system/tests/src/Functional/Form/StorageTest.php
+++ b/core/modules/system/tests/src/Functional/Form/StorageTest.php
@@ -7,7 +7,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Tests a multistep form using form storage.
+ * Tests a multistep form using form storage and makes sure validation and
+ * caching works right.
  *
  * The tested form puts data into the storage during the initial form
  * construction. These tests verify that there are no duplicate form
diff --git a/core/modules/system/tests/src/Functional/System/DateTimeTest.php b/core/modules/system/tests/src/Functional/System/DateTimeTest.php
index 5ba373205334c4048ee5b5014fc81eaf0b10143a..8a587973be64ad9eec9eecbb2d1790a0b09439df 100644
--- a/core/modules/system/tests/src/Functional/System/DateTimeTest.php
+++ b/core/modules/system/tests/src/Functional/System/DateTimeTest.php
@@ -7,7 +7,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Test date formatting and time zone handling, including daylight saving time.
+ * Configure date and time settings. Test date formatting and time zone
+ * handling, including daylight saving time.
  *
  * @group system
  */
diff --git a/core/modules/system/tests/src/Functional/System/ThemeTest.php b/core/modules/system/tests/src/Functional/System/ThemeTest.php
index 3ae9a3beec78b08ec2276db17d5182aca588ab09..d512d9320a41b098cd5c8aee10de507432e11aed 100644
--- a/core/modules/system/tests/src/Functional/System/ThemeTest.php
+++ b/core/modules/system/tests/src/Functional/System/ThemeTest.php
@@ -9,7 +9,8 @@
 use Drupal\Tests\TestFileCreationTrait;
 
 /**
- * Tests the theme administration user interface.
+ * Tests the theme interface functionality by enabling and switching themes, and
+ * using an administration theme.
  *
  * @group system
  */
diff --git a/core/modules/system/tests/src/Functional/Theme/EntityFilteringThemeTest.php b/core/modules/system/tests/src/Functional/Theme/EntityFilteringThemeTest.php
index 0e84329a54012aaf2849555403fcb8a88e18bc13..e5330bab36b478bf460666020a129db83a1c0231 100644
--- a/core/modules/system/tests/src/Functional/Theme/EntityFilteringThemeTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/EntityFilteringThemeTest.php
@@ -13,7 +13,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Tests XSS filtering for themed output for each entity type in all themes.
+ * Tests themed output for each entity type in all available themes to ensure
+ * entity labels are filtered for XSS.
  *
  * @group Theme
  */
diff --git a/core/modules/system/tests/src/Functional/Theme/ThemeEarlyInitializationTest.php b/core/modules/system/tests/src/Functional/Theme/ThemeEarlyInitializationTest.php
index 4dab6c2ded1b5e7154ddb1095f86578eae03d987..a01778dd317192623d0e30a9fdea23bd0d5323a9 100644
--- a/core/modules/system/tests/src/Functional/Theme/ThemeEarlyInitializationTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/ThemeEarlyInitializationTest.php
@@ -5,7 +5,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Tests theme system initialization early in the page request.
+ * Tests that the theme system can be correctly initialized early in the page
+ * request.
  *
  * @group Theme
  */
diff --git a/core/modules/system/tests/src/Functional/UpdateSystem/DependencyHookInvocationTest.php b/core/modules/system/tests/src/Functional/UpdateSystem/DependencyHookInvocationTest.php
index 561ff795af2b535a3b40f0ddc12e6a7ea6168670..d263380924b6c9d4bc80b7005a68f5f12030e01f 100644
--- a/core/modules/system/tests/src/Functional/UpdateSystem/DependencyHookInvocationTest.php
+++ b/core/modules/system/tests/src/Functional/UpdateSystem/DependencyHookInvocationTest.php
@@ -5,7 +5,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Tests the hook invocation for determining update dependencies.
+ * Tests that the hook invocation for determining update dependencies works
+ * correctly.
  *
  * @group Update
  */
diff --git a/core/modules/system/tests/src/Functional/UpdateSystem/InvalidUpdateHookTest.php b/core/modules/system/tests/src/Functional/UpdateSystem/InvalidUpdateHookTest.php
index 0d79aa906d9b442d9cf3713931bf6780b97249e7..8412ab1f0e528ee670338d43b4b1476408af85c0 100644
--- a/core/modules/system/tests/src/Functional/UpdateSystem/InvalidUpdateHookTest.php
+++ b/core/modules/system/tests/src/Functional/UpdateSystem/InvalidUpdateHookTest.php
@@ -7,7 +7,8 @@
 use Drupal\Tests\RequirementsPageTrait;
 
 /**
- * Tests that hook_update_8000() is disallowed.
+ * Tests that a module implementing hook_update_8000() causes an error to be
+ * displayed on update.
  *
  * @group Update
  */
diff --git a/core/modules/system/tests/src/Functional/UpdateSystem/UpdatesWith7xTest.php b/core/modules/system/tests/src/Functional/UpdateSystem/UpdatesWith7xTest.php
index 2364e99bdd863fabe7a3dc72e7fab11101ea6a15..e12b58687314384245286c7a2b147a9d44feb5a8 100644
--- a/core/modules/system/tests/src/Functional/UpdateSystem/UpdatesWith7xTest.php
+++ b/core/modules/system/tests/src/Functional/UpdateSystem/UpdatesWith7xTest.php
@@ -7,7 +7,8 @@
 use Drupal\Tests\RequirementsPageTrait;
 
 /**
- * Tests the minimum schema version when only 7.x update hooks are retained.
+ * Tests that the minimum schema version is correct even if only 7.x update
+ * hooks are retained .
  *
  * @group Update
  */
diff --git a/core/modules/system/tests/src/Kernel/Common/UrlTest.php b/core/modules/system/tests/src/Kernel/Common/UrlTest.php
index 22791a7a85324f627d90fbd6694d81893f7de4b5..6ed9d626e3fd7a1aeedc8b4e336cc8e19c9df4f5 100644
--- a/core/modules/system/tests/src/Kernel/Common/UrlTest.php
+++ b/core/modules/system/tests/src/Kernel/Common/UrlTest.php
@@ -12,10 +12,11 @@
 use Drupal\KernelTests\KernelTestBase;
 
 /**
- * Tests the Url object.
- *
- * @covers \Drupal\Component\Utility\UrlHelper::filterQueryParameters()
- * @covers \Drupal\Core\Utility\LinkGeneratorInterface::generate()
+ * Confirm that \Drupal\Core\Url,
+ * \Drupal\Component\Utility\UrlHelper::filterQueryParameters(),
+ * \Drupal\Component\Utility\UrlHelper::buildQuery(), and
+ * \Drupal\Core\Utility\LinkGeneratorInterface::generate()
+ * work correctly with various input.
  *
  * @group Common
  */
diff --git a/core/modules/system/tests/src/Kernel/Token/TokenReplaceKernelTest.php b/core/modules/system/tests/src/Kernel/Token/TokenReplaceKernelTest.php
index 2ecff8dcbe6a28bbf971bc92bfcf5ace0dcaf4dd..06fa062ddd5a44b495925ea9f78305df1204f264 100644
--- a/core/modules/system/tests/src/Kernel/Token/TokenReplaceKernelTest.php
+++ b/core/modules/system/tests/src/Kernel/Token/TokenReplaceKernelTest.php
@@ -10,7 +10,8 @@
 use Symfony\Component\HttpFoundation\Request;
 
 /**
- * Tests token replacement.
+ * Generates text using placeholders for dummy content to check token
+ * replacement.
  *
  * @group system
  */
diff --git a/core/modules/taxonomy/tests/src/Functional/RssTest.php b/core/modules/taxonomy/tests/src/Functional/RssTest.php
index 9b434d12928ac54b5039ffc2ac68699281da93dd..6558da831831bfb6db4715807e5c42f4274d9965 100644
--- a/core/modules/taxonomy/tests/src/Functional/RssTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/RssTest.php
@@ -6,7 +6,8 @@
 use Drupal\views\Views;
 
 /**
- * Tests the taxonomy RSS display.
+ * Ensure that data added as terms appears in RSS feeds if "RSS Category" format
+ * is selected.
  *
  * @group taxonomy
  */
diff --git a/core/modules/taxonomy/tests/src/Functional/TokenReplaceTest.php b/core/modules/taxonomy/tests/src/Functional/TokenReplaceTest.php
index 87e2811af9d2ec3c128075e4e445221ab2b8d6e4..383853ab28cd9b274b31e4ae29776609b6dd3b08 100644
--- a/core/modules/taxonomy/tests/src/Functional/TokenReplaceTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/TokenReplaceTest.php
@@ -6,7 +6,8 @@
 use Drupal\Core\Render\BubbleableMetadata;
 
 /**
- * Tests taxonomy token replacement.
+ * Generates text using placeholders for dummy content to check taxonomy token
+ * replacement.
  *
  * @group taxonomy
  */
diff --git a/core/modules/update/tests/src/Functional/UpdateContribTest.php b/core/modules/update/tests/src/Functional/UpdateContribTest.php
index 294074c592e92f47bd51a8751e0d4602cd8e3e8f..20a0d5eda32a8479050108c41a7ec0b272484b8f 100644
--- a/core/modules/update/tests/src/Functional/UpdateContribTest.php
+++ b/core/modules/update/tests/src/Functional/UpdateContribTest.php
@@ -6,7 +6,8 @@
 use Drupal\update\UpdateManagerInterface;
 
 /**
- * Tests how the Update Manager handles contributed modules and themes.
+ * Tests how the Update Manager module handles contributed modules and themes in
+ * a series of functional tests using mock XML data.
  *
  * @group update
  */
diff --git a/core/modules/update/tests/src/Functional/UpdateSemverCoreTest.php b/core/modules/update/tests/src/Functional/UpdateSemverCoreTest.php
index 829b68dd7b308d8ef86bdc150eab855edb01cff7..d740425fbd602f997e355cd156e749b968f90902 100644
--- a/core/modules/update/tests/src/Functional/UpdateSemverCoreTest.php
+++ b/core/modules/update/tests/src/Functional/UpdateSemverCoreTest.php
@@ -5,7 +5,8 @@
 use Drupal\Core\Url;
 
 /**
- * Tests the semantic version handling in the Update Manager.
+ * Tests the Update Manager module through a series of functional tests using
+ * mock XML data.
  *
  * @group update
  */
diff --git a/core/modules/user/tests/src/Functional/UserLanguageCreationTest.php b/core/modules/user/tests/src/Functional/UserLanguageCreationTest.php
index 4f3478542ae97681f805e9fea866de7152b1fb3b..94d86b492a74bfc2d74403eefb7ccaebb6d71af3 100644
--- a/core/modules/user/tests/src/Functional/UserLanguageCreationTest.php
+++ b/core/modules/user/tests/src/Functional/UserLanguageCreationTest.php
@@ -6,7 +6,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Tests preferred language configuration and language selector access.
+ * Tests whether proper language is stored for new users and access to language
+ * selector.
  *
  * @group user
  */
diff --git a/core/modules/user/tests/src/Functional/UserPermissionsTest.php b/core/modules/user/tests/src/Functional/UserPermissionsTest.php
index c79c470d8c8c06b1d00be3373ea2b14fe9a3b41b..1c5be8689d07fd6d5013ea0cff7cf70334de4ef8 100644
--- a/core/modules/user/tests/src/Functional/UserPermissionsTest.php
+++ b/core/modules/user/tests/src/Functional/UserPermissionsTest.php
@@ -7,7 +7,8 @@
 use Drupal\user\Entity\Role;
 
 /**
- * Verifies role permissions can be added and removed via the permissions page.
+ * Verify that role permissions can be added and removed via the permissions
+ * pages.
  *
  * @group user
  */
diff --git a/core/modules/user/tests/src/Functional/UserSearchTest.php b/core/modules/user/tests/src/Functional/UserSearchTest.php
index 5c013cdbfd11c675b0c4ce40be4f4af24cb0a4ae..973dc260266ff6219d677d913bdf2c299bb57011 100644
--- a/core/modules/user/tests/src/Functional/UserSearchTest.php
+++ b/core/modules/user/tests/src/Functional/UserSearchTest.php
@@ -5,7 +5,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Verifies that sensitive information is hidden from unauthorized users.
+ * Tests the user search page and verifies that sensitive information is hidden
+ * from unauthorized users.
  *
  * @group user
  */
diff --git a/core/modules/user/tests/src/Functional/UserTokenReplaceTest.php b/core/modules/user/tests/src/Functional/UserTokenReplaceTest.php
index 2857268a2533958e901765e373cab806a1683a72..2649f7a8f0ba91d9c1251a8288d64ab96353e1ec 100644
--- a/core/modules/user/tests/src/Functional/UserTokenReplaceTest.php
+++ b/core/modules/user/tests/src/Functional/UserTokenReplaceTest.php
@@ -9,7 +9,8 @@
 use Drupal\user\Entity\User;
 
 /**
- * Tests the replacement of user tokens.
+ * Generates text using placeholders for dummy content to check user token
+ * replacement.
  *
  * @group user
  */
diff --git a/core/modules/user/tests/src/Kernel/UserAccountFormFieldsTest.php b/core/modules/user/tests/src/Kernel/UserAccountFormFieldsTest.php
index dbc61853452dd715ab5d5a55ca31e7f794bc347d..1aabea79a8a533ca6210b670afac9636e2a64081 100644
--- a/core/modules/user/tests/src/Kernel/UserAccountFormFieldsTest.php
+++ b/core/modules/user/tests/src/Kernel/UserAccountFormFieldsTest.php
@@ -6,7 +6,8 @@
 use Drupal\KernelTests\KernelTestBase;
 
 /**
- * Verifies the field order in user account forms.
+ * Verifies that the field order in user account forms is compatible with
+ * password managers of web browsers.
  *
  * @group user
  */
diff --git a/core/modules/user/tests/src/Kernel/UserActionConfigSchemaTest.php b/core/modules/user/tests/src/Kernel/UserActionConfigSchemaTest.php
index 8767c92e159601d79daead9d7fad0ba27861c93e..527db24aa41c19ace346136c5297e6507399967b 100644
--- a/core/modules/user/tests/src/Kernel/UserActionConfigSchemaTest.php
+++ b/core/modules/user/tests/src/Kernel/UserActionConfigSchemaTest.php
@@ -7,7 +7,8 @@
 use Drupal\user\Entity\Role;
 
 /**
- * Tests that the config schema is valid when roles are added or removed.
+ * Ensures the user action for adding and removing roles have valid config
+ * schema.
  *
  * @group user
  */
diff --git a/core/modules/user/tests/src/Traits/UserCreationTrait.php b/core/modules/user/tests/src/Traits/UserCreationTrait.php
index 683ba355c8ad4e8a5e567730c94ac3d84e092e80..92a3101e1816dd323064d6c946a1b4e199151f8d 100644
--- a/core/modules/user/tests/src/Traits/UserCreationTrait.php
+++ b/core/modules/user/tests/src/Traits/UserCreationTrait.php
@@ -13,7 +13,8 @@
 use Drupal\user\RoleInterface;
 
 /**
- * Provides test methods for user creation and authentication.
+ * Provides methods to create additional test users and switch the currently
+ * logged in one.
  *
  * This trait is meant to be used only by test classes.
  */
diff --git a/core/modules/views/tests/src/Functional/Wizard/ItemsPerPageTest.php b/core/modules/views/tests/src/Functional/Wizard/ItemsPerPageTest.php
index 61da043cf2dfa1d86fb2be35ebc6627cd4b04f1f..da9ac54e063e8af04ae18fb9baf1a4414a58dffe 100644
--- a/core/modules/views/tests/src/Functional/Wizard/ItemsPerPageTest.php
+++ b/core/modules/views/tests/src/Functional/Wizard/ItemsPerPageTest.php
@@ -3,7 +3,8 @@
 namespace Drupal\Tests\views\Functional\Wizard;
 
 /**
- * Tests that the views wizard can specify the number of items per page.
+ * Tests the ability of the views wizard to specify the number of items per
+ * page.
  *
  * @group views
  */
diff --git a/core/modules/views/tests/src/Kernel/Handler/FilterBooleanOperatorStringTest.php b/core/modules/views/tests/src/Kernel/Handler/FilterBooleanOperatorStringTest.php
index 66bac02a642f09db3fcbeac8cf405958aabf3956..88c3de207aa3f8a6a45241507c2c81872d362c48 100644
--- a/core/modules/views/tests/src/Kernel/Handler/FilterBooleanOperatorStringTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/FilterBooleanOperatorStringTest.php
@@ -6,7 +6,8 @@
 use Drupal\views\Views;
 
 /**
- * Tests core's BooleanOperatorString views filter handler.
+ * Tests the core Drupal\views\Plugin\views\filter\BooleanOperatorString
+ * handler.
  *
  * @group views
  * @see \Drupal\views\Plugin\views\filter\BooleanOperatorString
diff --git a/core/profiles/testing/modules/drupal_system_listing_compatible_test/tests/src/Kernel/SystemListingCrossProfileCompatibleTest.php b/core/profiles/testing/modules/drupal_system_listing_compatible_test/tests/src/Kernel/SystemListingCrossProfileCompatibleTest.php
index cc4ec230e12389cf04b5ecce902dfe8df67880da..d3a9f0d7e8a65594331795856f76741ea726ebc8 100644
--- a/core/profiles/testing/modules/drupal_system_listing_compatible_test/tests/src/Kernel/SystemListingCrossProfileCompatibleTest.php
+++ b/core/profiles/testing/modules/drupal_system_listing_compatible_test/tests/src/Kernel/SystemListingCrossProfileCompatibleTest.php
@@ -5,7 +5,8 @@
 use Drupal\KernelTests\KernelTestBase;
 
 /**
- * Verifies that tests in installation profile modules are found.
+ * Verifies that tests in installation profile modules are found and may use
+ * another profile for running tests.
  *
  * @group drupal_system_listing_compatible_test
  */
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/MultiFormTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/MultiFormTest.php
index d436179b41447f8e9f8d20b5b6fe5d858a69f0fe..83c26e96e1a6dfa5c5e1448c0cc756e170e15152 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/MultiFormTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/MultiFormTest.php
@@ -8,7 +8,8 @@
 use Drupal\FunctionalJavascriptTests\WebDriverTestBase;
 
 /**
- * Tests AJAX-enabled forms when multiple instances of the form are on a page.
+ * Tests that AJAX-enabled forms work when multiple instances of the same form
+ * are on a page.
  *
  * @group Ajax
  */
diff --git a/core/tests/Drupal/FunctionalTests/FolderTest.php b/core/tests/Drupal/FunctionalTests/FolderTest.php
index 923849e561c8143512971ed877354e2250783d53..a8196ebd92555f662fce6b9f532f8552daa9aa23 100644
--- a/core/tests/Drupal/FunctionalTests/FolderTest.php
+++ b/core/tests/Drupal/FunctionalTests/FolderTest.php
@@ -5,8 +5,8 @@
 use Drupal\Tests\BrowserTestBase;
 
 /**
- * Tests BrowserTestBase's treatment of hook_install() during setup.
- *
+ * This test will check BrowserTestBase's treatment of hook_install during
+ * setUp.
  * Image module is used for test.
  *
  * @group browsertestbase
diff --git a/core/tests/Drupal/FunctionalTests/Installer/InstallerExistingDatabaseSettingsTest.php b/core/tests/Drupal/FunctionalTests/Installer/InstallerExistingDatabaseSettingsTest.php
index 53a615b57cd57a95ad5291d51fc794678a7d8498..ee6caea944fc6d3275671cbb9949bf20bebb757b 100644
--- a/core/tests/Drupal/FunctionalTests/Installer/InstallerExistingDatabaseSettingsTest.php
+++ b/core/tests/Drupal/FunctionalTests/Installer/InstallerExistingDatabaseSettingsTest.php
@@ -5,7 +5,8 @@
 use Drupal\Core\Database\Database;
 
 /**
- * Tests installation with database information in an existing settings file.
+ * Tests the installer with an existing settings file with database connection
+ * info.
  *
  * @group Installer
  */
diff --git a/core/tests/Drupal/FunctionalTests/Installer/InstallerSiteConfigProfileTest.php b/core/tests/Drupal/FunctionalTests/Installer/InstallerSiteConfigProfileTest.php
index c09bf838e4ed3f83f3a6d3067e773daa0628fbaa..097d8451891fccaab0fabf3485cbc016c2cfad2f 100644
--- a/core/tests/Drupal/FunctionalTests/Installer/InstallerSiteConfigProfileTest.php
+++ b/core/tests/Drupal/FunctionalTests/Installer/InstallerSiteConfigProfileTest.php
@@ -3,7 +3,8 @@
 namespace Drupal\FunctionalTests\Installer;
 
 /**
- * Verifies that the installer uses the profile's site configuration.
+ * Verifies that the installer defaults to the existing site email address and
+ * timezone, if they were provided by the install profile.
  *
  * @group Installer
  */
diff --git a/core/tests/Drupal/FunctionalTests/MailCaptureTest.php b/core/tests/Drupal/FunctionalTests/MailCaptureTest.php
index 67f0099704f04ab4684ade48cb3a779077344491..d4bc642e714f55aa9e4ec2c5f939b3f91bdeb79e 100644
--- a/core/tests/Drupal/FunctionalTests/MailCaptureTest.php
+++ b/core/tests/Drupal/FunctionalTests/MailCaptureTest.php
@@ -7,10 +7,8 @@
 use Drupal\Core\Test\AssertMailTrait;
 
 /**
- * Tests the collection of emails during testing.
- *
- * The test mail collector, test.mail.collector, intercepts any email sent
- * during a test so it does not leave the test server.
+ * Tests the email capturing logic, the assertMail assertion and the
+ * drupalGetMails function.
  *
  * @group browsertestbase
  */
diff --git a/core/tests/Drupal/KernelTests/Core/Common/SizeTest.php b/core/tests/Drupal/KernelTests/Core/Common/SizeTest.php
index 77e70784ee34829961f161e41fbcf411f2639199..f595cfcab5ec8dbfa2bf5aed11099fe62acae4ab 100644
--- a/core/tests/Drupal/KernelTests/Core/Common/SizeTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Common/SizeTest.php
@@ -6,7 +6,8 @@
 use Drupal\KernelTests\KernelTestBase;
 
 /**
- * Tests format_size().
+ * Parse a predefined amount of bytes and compare the output with the expected
+ * value.
  *
  * @group Common
  */
diff --git a/core/tests/Drupal/KernelTests/Core/Common/XssUnitTest.php b/core/tests/Drupal/KernelTests/Core/Common/XssUnitTest.php
index 38edb98d36abbbb260ce137f29ba6e55591fb043..ff7fba57ffacf2fa8318305405f71157dcb5c055 100644
--- a/core/tests/Drupal/KernelTests/Core/Common/XssUnitTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Common/XssUnitTest.php
@@ -6,11 +6,8 @@
 use Drupal\KernelTests\KernelTestBase;
 
 /**
- * Tests XSS filtering.
- *
- * @see \Drupal\Component\Utility\Xss::filter()
- * @see \Drupal\Component\Utility\UrlHelper::filterBadProtocol
- * @see \Drupal\Component\Utility\UrlHelper::stripDangerousProtocols
+ * Confirm that \Drupal\Component\Utility\Xss::filter() and check_url() work
+ * correctly, including invalid multi-byte sequences.
  *
  * @group Common
  */
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityStorageTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityStorageTest.php
index 325d5cd66a5150f2063775c7fa01da6679f0a9c3..91887ecc59e68da959c928778c52e57c1d17d325 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityStorageTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityStorageTest.php
@@ -6,7 +6,8 @@
 use Drupal\KernelTests\KernelTestBase;
 
 /**
- * Tests configuration entity storage.
+ * Tests sync and importing config entities with IDs and UUIDs that match
+ * existing config.
  *
  * @group config
  */
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigOverridesPriorityTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigOverridesPriorityTest.php
index b5ca02e95613efec16625c99fbe26d5b995b5377..7ad4487796e8661153cda2883cfd97fd8e841bac 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigOverridesPriorityTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigOverridesPriorityTest.php
@@ -6,13 +6,8 @@
 use Drupal\KernelTests\KernelTestBase;
 
 /**
- * Tests that config overrides are applied in the correct order.
- *
- * Overrides should be applied in the following order, from lowest priority
- * to highest:
- * - Language overrides.
- * - Module overrides.
- * - settings.php overrides.
+ * Tests that language, module and settings.php are applied in the correct
+ * order.
  *
  * @group config
  */
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityCrudHookTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityCrudHookTest.php
index ff9c257fb4275d4604fd44a106852e0977287a81..3cd38553131409473b9d44386194c1d0f6c7c0e8 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityCrudHookTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityCrudHookTest.php
@@ -16,8 +16,6 @@
 use Drupal\file\Entity\File;
 
 /**
- * Tests entity CRUD via hooks.
- *
  * Tests the invocation of hooks when creating, inserting, loading, updating or
  * deleting an entity.
  *
diff --git a/core/tests/Drupal/KernelTests/Core/File/FileTestBase.php b/core/tests/Drupal/KernelTests/Core/File/FileTestBase.php
index ac0376d69622679d898f1215cbc73436663ddfa9..fe523eecf07158bb7c3fe422ac131b7adc37cc58 100644
--- a/core/tests/Drupal/KernelTests/Core/File/FileTestBase.php
+++ b/core/tests/Drupal/KernelTests/Core/File/FileTestBase.php
@@ -6,7 +6,8 @@
 use Drupal\KernelTests\KernelTestBase;
 
 /**
- * Provides file-specific assertions and helper functions.
+ * Base class for file tests that adds some additional file specific
+ * assertions and helper functions.
  */
 abstract class FileTestBase extends KernelTestBase {
 
diff --git a/core/tests/Drupal/KernelTests/Core/Form/FormCacheTest.php b/core/tests/Drupal/KernelTests/Core/Form/FormCacheTest.php
index fe8d614c88a68894c91139541d162918f0b9770a..9d89caa87ab7a636af50f71dc4b26861c6495347 100644
--- a/core/tests/Drupal/KernelTests/Core/Form/FormCacheTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Form/FormCacheTest.php
@@ -9,10 +9,8 @@
 use Drupal\KernelTests\KernelTestBase;
 
 /**
- * Tests FormBuilder caching.
- *
- * @covers \Drupal\Core\Form\FormBuilder::getCache
- * @covers \Drupal\Core\Form\FormBuilder::setCache
+ * Tests \Drupal::formBuilder()->setCache() and
+ * \Drupal::formBuilder()->getCache().
  *
  * @group Form
  */
diff --git a/core/tests/Drupal/KernelTests/Core/Plugin/Condition/RequestPathTest.php b/core/tests/Drupal/KernelTests/Core/Plugin/Condition/RequestPathTest.php
index efbbd9113ef5394e5417bf1aefb8806e82e4a44f..be6ec023eeb3162b4f598adb5b1b68142f5d9acb 100644
--- a/core/tests/Drupal/KernelTests/Core/Plugin/Condition/RequestPathTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Plugin/Condition/RequestPathTest.php
@@ -9,7 +9,8 @@
 use Symfony\Component\HttpFoundation\RequestStack;
 
 /**
- * Tests system.module's request path condition.
+ * Tests that the Request Path Condition, provided by the system module, is
+ * working properly.
  *
  * @group Plugin
  */
diff --git a/core/tests/Drupal/KernelTests/Core/Plugin/Discovery/CustomDirectoryAnnotatedClassDiscoveryTest.php b/core/tests/Drupal/KernelTests/Core/Plugin/Discovery/CustomDirectoryAnnotatedClassDiscoveryTest.php
index c65f0e14f0ec7db19d3d4540f4a825da031f1790..48f987decceba22d1243a43aeca882d972dc7691 100644
--- a/core/tests/Drupal/KernelTests/Core/Plugin/Discovery/CustomDirectoryAnnotatedClassDiscoveryTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Plugin/Discovery/CustomDirectoryAnnotatedClassDiscoveryTest.php
@@ -6,7 +6,8 @@
 use Drupal\Core\StringTranslation\TranslatableMarkup;
 
 /**
- * Tests discovery of annotated plugins in a custom directory.
+ * Tests that plugins in a custom directory are correctly discovered using
+ * annotated classes.
  *
  * @group Plugin
  */
diff --git a/core/tests/Drupal/KernelTests/Core/TypedData/ComplexDataConstraintValidatorTest.php b/core/tests/Drupal/KernelTests/Core/TypedData/ComplexDataConstraintValidatorTest.php
index 0d9d06d79710786a26627271305d612aa5b87362..94b1b33aa934a6818b41d92ab8dbbfb9be31dc23 100644
--- a/core/tests/Drupal/KernelTests/Core/TypedData/ComplexDataConstraintValidatorTest.php
+++ b/core/tests/Drupal/KernelTests/Core/TypedData/ComplexDataConstraintValidatorTest.php
@@ -7,7 +7,8 @@
 use Drupal\KernelTests\KernelTestBase;
 
 /**
- * Tests ComplexData validation with both valid and invalid values.
+ * Tests ComplexData validation constraint with both valid and invalid values
+ * for a key.
  *
  * @group Validation
  */