---
phase: 19-methodology-guidance-and-polaris
plan: "03"
subsystem: check
tags: [polaris, check, alignment, ActionDefinition, TDD]

requires:
  - phase: 19-01
    provides: polaris.md scaffolded in vault init, ContextAssembler polaris layer

provides:
  - check_alignment service method in CheckService
  - check_alignment controller method in CheckController
  - check_alignment ActionDefinition registered in check category
  - Auto-generated ztlctl check alignment CLI surface
  - Auto-generated check_alignment MCP tool

affects: [mcp, cli, agents, phase-20, phase-21]

tech-stack:
  added: []
  patterns:
    - "keyword-overlap heuristic for polaris priority matching (stopword-filtered set intersection)"
    - "advisory alignment check: aligned always True, never blocks action execution"

key-files:
  created: []
  modified:
    - src/ztlctl/services/check.py
    - src/ztlctl/controllers/check.py
    - src/ztlctl/actions/_check.py
    - tests/services/test_check.py
    - tests/actions/test_core_registrations.py

key-decisions:
  - "aligned is always True — check_alignment is purely advisory, never blocks"
  - "keyword-overlap heuristic uses stopword-filtered set intersection (no NLP dependency)"
  - "check_alignment registered in check category with cli_name=alignment"

patterns-established:
  - "Polaris alignment: heuristic keyword match between decision text and priority/principle lines"

requirements-completed: [POLR-04]

duration: 8min
completed: "2026-03-21"
---

# Phase 19 Plan 03: check_alignment Action Summary

**check_alignment action: polaris-based advisory decision alignment using keyword-overlap heuristic, auto-generating ztlctl check alignment CLI and check_alignment MCP tool**

## Performance

- **Duration:** ~8 min
- **Started:** 2026-03-21T19:05:00Z
- **Completed:** 2026-03-21T19:08:14Z
- **Tasks:** 1 (TDD: RED + GREEN commits)
- **Files modified:** 5

## Accomplishments

- `CheckService.check_alignment` reads polaris.md, extracts priorities and decision principles under their respective headings, computes stopword-filtered keyword overlap, and returns structured `{aligned, relevant_priorities, reasoning, polaris_exists}` result
- `CheckController.check_alignment` delegates via `_run_action` pattern consistent with all other controller methods
- `ActionDefinition` registered under check category with `cli_name="alignment"` and `side_effect="read"` — auto-generates `ztlctl check alignment` CLI command and `check_alignment` MCP tool
- 8 tests covering: no-polaris path, data structure contract, keyword overlap detection, empty-overlap case, and always-true `aligned` invariant

## Task Commits

Each task was committed atomically (TDD):

1. **RED: failing tests** - `d9fca5f` (test)
2. **GREEN: implementation** - `4ff3d4a` (feat)

**Plan metadata:** (docs commit follows)

_Note: TDD task — two commits (test → feat)_

## Files Created/Modified

- `src/ztlctl/services/check.py` - Added `check_alignment` method with polaris parsing and keyword-overlap heuristic
- `src/ztlctl/controllers/check.py` - Added `check_alignment` controller delegating via `_run_action`
- `src/ztlctl/actions/_check.py` - Registered `check_alignment` ActionDefinition in check category
- `tests/services/test_check.py` - Added `TestCheckAlignment` class with 8 tests
- `tests/actions/test_core_registrations.py` - Updated check category exact-names set to include `check_alignment`

## Decisions Made

- `aligned` is always `True` — the check is advisory information for agents, never a gate
- Keyword-overlap heuristic uses stopword-filtered set intersection — no NLP dependency, lightweight and deterministic
- Registered under `check` category with `cli_name="alignment"` (command becomes `ztlctl check alignment`)

## Deviations from Plan

None — plan executed exactly as written.

## Issues Encountered

One pre-existing test failure (`tests/integration/test_verbose_telemetry.py::TestVerboseTelemetry::test_verbose_json_includes_telemetry_in_meta`) confirmed as pre-existing (fails on the base commit before any changes). Logged to deferred items.

## Next Phase Readiness

- POLR-04 satisfied: agents can call `check_alignment` to evaluate a decision against polaris priorities
- Phase 19 complete — all 3 plans done (METH-01/02/03, POLR-01/02/03/04)
- Polaris layer fully operational: scaffolded on init, surfaced in context assembler, queryable via check_alignment

---
*Phase: 19-methodology-guidance-and-polaris*
*Completed: 2026-03-21*
