### Problem/Motivation `InputTypeCoercionSubscriber` (priority 50) currently handles list-wrapping, boolean strings, and numeric strings. Real LLM traffic produces more recoverable shapes; each currently costs a validation-failure round-trip (failure message + `input_schema` echo → model retry). Principle: **coerce only when unambiguous** — anything doubtful stays for validation, whose correction loop already works. Nested coverage is free via the recursive subscriber's child dispatch. ### Proposed resolution (priority order) | \# | Gap | Fix | |----|-----|-----| | B1 | JSON _string_ for map/list input (`"{\"a\":1}"`) | If target is map/list/multiple and trimmed string starts `{`/`[`: json_decode, accept only if decoded type matches (assoc for map), else leave untouched — **High**, most common real failure mode | | B2 | Enum near-miss (`"Article"` vs `article`) | With Choice/AllowedValues constraint: case-insensitive + trimmed match → snap to canonical; no fuzzier matching | | B3 | Date formats for datetime inputs | DateTimeIso8601: parse via `\DateTimeImmutable`, re-emit ISO 8601; Timestamp: numeric string → int, parseable date → timestamp; unparseable stays for validation | | B4 | Integral float for integer (`5.0`) | Coerce when `fmod == 0` | | B5 | Int `0`/`1` for boolean | Coerce to bool | | B6 | `""` for optional non-string input | Coerce to NULL | ### Testing Extend `tests/src/Kernel/Tool/InputTypeCoercionTest.php` per case, **including "invalid stays invalid" negative assertions** so coercion never masks validation (the guard established when the silent-FALSE boolean regression was fixed). ### Notes - All additions live in the existing subscriber at priority 50; the invoker(100)/coercion(50)/recursive(-100) lattice is unchanged. - Post-1.0 this work only ever _loosens_ accepted input, which is BC-safe — hence not freeze-bound. Full analysis: `~/Documents/tool-schema-and-coercion-plan.md` (workstream B). ### 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. - [x] **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.