# AD-448 Wrapped Tool Executor Build Report

**Date:** 2026-04-30
**Status:** Complete
**Prompt:** `prompts/ad-448-wrapped-tool-executor.md`

## Summary

Implemented `ToolExecutor` as a decorator layer above `ToolRegistry.check_and_invoke()`. The executor supports pre-hooks, post-hooks, timing capture, pre-hook aborts, fail-open pre-hook exception handling, and a standard audit post-hook that emits `TOOL_INVOKED`.

`ToolRegistry.check_and_invoke()`, permission resolution, LOTO locking, and existing tool call sites were not changed.

## Files Changed

- `src/probos/tools/executor.py`
  - Added `InvocationContext`, `ToolExecutor`, hook types, and `make_audit_hook()`.
- `src/probos/events.py`
  - Added `EventType.TOOL_INVOKED`.
- `src/probos/startup/finalize.py`
  - Added finalize-time `ToolExecutor` initialization when `runtime.tool_registry` is available.
- `tests/test_ad448_wrapped_tool_executor.py`
  - Added 10 focused tests for executor delegation, hook behavior, timing, audit events, event existence, and hook counts.
- `PROGRESS.md`, `docs/development/roadmap.md`
  - Updated AD-448 tracking.

## Sections Implemented

- `### Section 1: Create ToolExecutor`
  - Implemented in `src/probos/tools/executor.py`.
- `### Section 2: Add TOOL_INVOKED event type`
  - Implemented in `src/probos/events.py` after `TOOL_PERMISSION_DENIED`.
- `### Section 3: Add default audit post-hook`
  - Implemented as `make_audit_hook()` in `src/probos/tools/executor.py`.
- `### Section 4: Wire ToolExecutor in startup`
  - Implemented in `src/probos/startup/finalize.py`.
- `## Tests`
  - Implemented in `tests/test_ad448_wrapped_tool_executor.py`.
- `## Tracking`
  - Updated `PROGRESS.md`, `docs/development/roadmap.md`, and this build report.

## Post-Build Section Audit

- `### Section 1: Create ToolExecutor` — complete; invocation context, pre/post hook registration, pre-hook aborts, fail-open pre-hook exceptions, post-hook execution, timing, registry delegation, and hook count exist.
- `### Section 2: Add TOOL_INVOKED event type` — complete; event type exists in `EventType`.
- `### Section 3: Add default audit post-hook` — complete; audit hook emits `TOOL_INVOKED` with agent, tool, duration, error, and timestamp fields.
- `### Section 4: Wire ToolExecutor in startup` — complete; finalization wires `runtime._tool_executor` with an audit hook when the registry exists.
- `## Tests` — complete; 10 focused tests added.
- `## Tracking` — complete; tracker and build report updates added.

## Tests

- `d:/ProbOS/.venv/Scripts/pytest.exe tests/test_ad448_wrapped_tool_executor.py -v -n 0`
  - Result: 10 passed.
- `d:/ProbOS/.venv/Scripts/pytest.exe tests/test_ad448_wrapped_tool_executor.py tests/test_ad423a_tool_foundation.py tests/test_ad423b_tool_permissions.py tests/test_ad423c_tool_context.py -v -n 0`
  - Result: 83 passed.
- `d:/ProbOS/.venv/Scripts/pytest.exe tests/ -q -n 4 --dist=loadfile`
  - Result: 10172 passed, 18 skipped.

## Deviations

- Added the review-recommended `invoke()` docstring note that pre-hook exceptions are logged and fail open.
- Added 1 test beyond the prompt's 9 to cover `hook_count`.
- Verified `ToolRegistry.check_and_invoke()` does not call back into `ToolExecutor`; no recursion guard was added.
