### Problem/Motivation The emitted input schemas omit several constraints and formats that tools already declare, so LLM/MCP consumers get weaker contracts than the typed-data layer enforces — costing correction round-trips. Constraint mapping is centralized in `ContextDefinitionNormalizer::getNormalizationSchema()` (currently: FixedValue, Choice, AllowedValues, PluginExists, Length, Range) and applies on both scalar paths (10.5 legacy normalizer / 11.1+ core normalizers — the selection bug was fixed in the beta3 cycle, and previous-major CI now tests both). Overlaps with #3582943 "Deliverable A" (enrich input schema) — this issue is the normalizer-side implementation. ### Proposed resolution (priority order) | \# | Gap | Fix | |----|-----|-----| | A1 | `Regex` constraint → `pattern` | Map in the constraint block; convert PCRE → ECMA-262 (strip delimiters/modifiers; skip with warning on unsupported modifiers like `u`) — **High** | | A2 | Decimal emits non-standard `type: string, format: number` | `type: string` + `pattern: ^-?\d+(\.\d+)?$` + "decimal as string" description (preserves precision semantics) — **High** | | A3 | No `format: date-time` on legacy path | `DateTimeIso8601` → `string` + `format: date-time`; `Timestamp` → `integer` + Unix-timestamp description (match-arm order matters; core's DateTimeNormalizer already covers 11.1+) | | A4 | Empty `properties` serializes as `[]` not `{}` | Represent empty properties as object at the schema edges (verified non-reproducing over live MCP transport — future raw consumers only, Low) | | A5 | No `additionalProperties: false` on objects | Emit on input root + maps (safe: execute() already drops undeclared values) | | A6/A7 | `Count` → `minItems`/`maxItems`; `GreaterThan`/`LessThan`(±OrEqual) → `exclusiveMinimum`/etc. | Straight mappings | | A8 | No `title`; description is "Label: Description" merged | Split `title`/`description` — **deliberate prompt-visible change, needs before/after eval; do last** | ### Testing Snapshot-style kernel test asserting the full emitted schema for a fixture covering every data type × constraint combination (extend `ComprehensiveTypesTool`), asserted on both scalar paths using the dual-format helpers (10.x emits `type: [X, null]`, 11.x emits `oneOf`). Full analysis with verified current-state notes: `~/Documents/tool-schema-and-coercion-plan.md` (workstream A). ### 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.