# Architecture Checklist: AI Tool Layer

**Created**: 2026-05-19
**Feature**: 225-ai-tool-layer-architecture

## System Architecture

- [x] Does not break any existing core functionality.
- [x] Fits within the described boundaries of ADR-023A and ADR-025.
- [x] Maintains isolation: AI Tool Layer does not directly access database, uses Domain Services.
- [x] Correctly implements Server-side intent routing.

## Security (CASL & Audit)

- [x] Every tool function enforces CASL rules using `CaslAbilityFactory`.
- [x] Audit logs are written for every tool execution.
- [x] ADR-019 check: No `id: number` exists in `ToolCallResult` data payloads.
- [x] No side effects (writes) allowed unless explicitly modeled and protected (Read-only predominantly for V1).

## Observability

- [x] All tool layer failures log the exception details to the server logs.
- [x] The `ToolCallResult` returns user-friendly messages for failures without leaking technical details.
