### Problem/Motivation `src/TypedInputsTrait.php` (\~lines 337-341), inside `validateInputValue()`: ```php if ($definition->isMultiple() && is_array($value)) { foreach ($value as $item) { $item_definition = clone $definition; $item_definition->setMultiple(FALSE); return $this->validateInputValue($item_definition, $item); } } ``` The `return` inside the first loop iteration means items 2..n of a multiple input are never validated — invalid values in later positions pass validation and reach `doExecute()`. This is a validation bypass, which matters doubly now that the AI connector feeds LLM-supplied values into tools. Note: #3553721 ("Fix validation on multiple value input definitions") is closed, but the defect is present in current 1.0.x — either the fix was incomplete or it regressed. This issue supersedes it. ### Steps to reproduce 1. Tool with a multiple integer input. 2. `$tool->setInputValue('numbers', [1, 'not a number']);` 3. `$tool->execute();` → executes with the invalid second item instead of returning an invalid-input failure. (`[1]` vs `['not a number', 1]` behave differently.) ### Proposed resolution Accumulate violations across all items: ```php foreach ($value as $item) { $item_definition = clone $definition; $item_definition->setMultiple(FALSE); $violations->addAll($this->validateInputValue($item_definition, $item)); } return $violations; ``` Also decide behavior for an empty array on a required multiple input (currently skips the else branch and returns no violations). Add kernel tests: invalid item in position 2 fails; all-valid passes; empty-array-on-required behavior pinned. ### AI usage (if applicable) - [x] **AI Assisted Issue:** This issue was generated with AI assistance, but was reviewed and refined by the creator. - [x] **AI Assisted Code:** This code was mainly generated by a human, with AI autocompleting or parts AI generated, but under full human supervision. - [ ] **AI Generated Code:** This code was mainly generated by an AI with human guidance, and reviewed, tested, and refined by a human. - [ ] **Vibe Coded:** This code was generated by an AI and has only been functionally tested.