>>> [!note] Migrated issue <!-- Drupal.org comment --> <!-- Migrated from issue #3595055. --> Reported by: [tim bozeman](https://www.drupal.org/user/2241356) >>> <h3 id="summary-problem-motivation">Problem/Motivation</h3> <p>Behavioral guidance for AI agents (how to compose a page, what workflow to follow before creating an entity, how to fit a new section into an existing layout) was carried in the system prompt. As a system prompt grows, individual instructions become less salient and the model loses awareness of them, and every conversation pays the token cost of guidance it may never use. Guidance should arrive only when the task at hand actually calls for it.</p> <h3 id="summary-proposed-resolution">Proposed resolution</h3> <p>Add a <strong>skills</strong> system: named bundles of behavioral guidance the AI loads on demand. The conversation carries only a catalog (skill id + description); the full instructions arrive through the <code>eb_skill</code> tool when a skill matches the task. This mirrors how Claude Code surfaces skills.</p> <ul> <li><strong><code>SkillsResolver</code></strong> discovers <code>MODULE.entity_blueprint.skills.SKILL_ID.yml</code> definitions across all modules (label, description, type, instructions), then runs <code>hook_entity_blueprint_skills_alter()</code>. Cached.</li> <li><strong><code>SkillTypeManager</code></strong> &mdash; a tagged service collector (<code>entity_blueprint.skill_type</code>) whose plugins compose a skill's response from its definition plus invocation parameters: <code>DefaultSkillType</code> (verbatim), <code>CreateEntitySkillType</code> (visible bundle catalog + a blocking pick-bundle/read-schema/plan checklist), and <code>CurrentEntitySkillType</code> (bundle-specific guidance for the entity the user is on).</li> <li>The shared YAML-discovery-plus-hook merge is extracted from <code>BlueprintContextResolver</code> and <code>ManagedKeysRegistry</code> into <code>YamlDiscoveryTrait</code>, reused by <code>SkillsResolver</code>. <code>BundleListBuilder</code> and <code>CurrentEntityContext</code> are added as composition inputs.</li> <li>Provider-specific wiring lives in a new <code>entity_blueprint_ai_anthropic</code> submodule so the skill format can be tuned per provider. Its <code>SkillListSubscriber</code> performs a two-part injection: a <code>## Skills</code> instruction block on <code>BuildSystemPromptEvent</code> (the obligation to check skills before acting), and a <code>&amp;lt;system-reminder&amp;gt;</code> skill catalog prepended to the first user message on <code>AiAssistantPassContextToAgentEvent</code>.</li> <li>Ships two skill definitions: <code>create_entity</code> and <code>add_section</code>.</li> </ul> <h3 id="summary-api-changes">API changes</h3> <ul> <li>New services: <code>entity_blueprint.skills_resolver</code> (<code>SkillsResolverInterface</code>), <code>entity_blueprint.skill_type_manager</code>, the three skill-type services, <code>entity_blueprint.bundle_list_builder</code>, and <code>entity_blueprint.current_entity_context</code>.</li> <li>New AI tool <code>eb_skill</code> for loading a skill's composed guidance.</li> <li>New extension points: the <code>MODULE.entity_blueprint.skills.SKILL_ID.yml</code> discovery convention, <code>hook_entity_blueprint_skills_alter()</code>, and the <code>entity_blueprint.skill_type</code> tagged service (<code>SkillTypeInterface::compose()</code>, tagged with <code>type_id</code>).</li> <li>New submodule <code>entity_blueprint_ai_anthropic</code> (depends on <code>entity_blueprint_ai</code>, <code>ai_agents</code>; <code>lifecycle: experimental</code>), subscribing to <code>BuildSystemPromptEvent</code> and <code>AiAssistantPassContextToAgentEvent</code>. Other providers can subscribe similarly to surface skills their own way.</li> <li>Internal refactor: <code>BlueprintContextResolver</code> and <code>ManagedKeysRegistry</code> now use <code>YamlDiscoveryTrait</code>; discovery behavior and three-layer precedence (universal YAML &rarr; scoped YAML &rarr; hook) are unchanged.</li> </ul>