# 003 — Elaborate process_tools docs/ to Level 2
## Status: ✅ Done
- **ID:** 003
- **Priority:** 2
- **Executor:** any
- **Advisability:** 480
- **Value:** 6 / Easiness:** 7 / Safety:** 9
## Purpose
The `docs/` hierarchy created during spec.md migration contains Level 1 stubs (H1 title + one-paragraph statement). Elaborate each doc instance to Level 2 by adding concrete implementation details, code examples, cross-references, and behavioral constraints drawn from the source code.
## Context
After the spec.md → docs/ migration (task implicit in session):
- `docs/feature/` has 5 instances at Level 1
- `docs/api/` has 4 instances at Level 1
- `docs/invariant/` has 2 instances at Level 1
Level 2 adds: ### Implementation Notes, ### Examples (with real code), ### See Also cross-references, and for API docs: full function signatures with doc-comment alignment.
The `exit_status` (task 002) and `lifecycle` (task 001) modules are newly added and have no prior documentation beyond what's in source code doc-comments. These need the most elaboration.
## MOST Goals
1. All 11 doc instances have at least `### Statement` + `### Implementation Notes` + one `### Example` — `find docs/ -name "*.md" ! -name "readme.md" | xargs grep -l "### Example"` returns 11 files
2. API docs match current public function signatures — `grep -r "fn " docs/api/` signatures match `src/`
3. Exit status and lifecycle docs explicitly document platform constraints — `grep -l "cfg(unix)\|Unix" docs/feature/` returns at least 2 files
4. Cross-references exist between related docs — `grep -rl "See Also" docs/` returns ≥ 5 files
## Validation Criteria (Done When)
- [ ] `find docs/ -name "*.md" ! -name "readme.md" | wc -l` → 11
- [ ] `find docs/ -name "*.md" ! -name "readme.md" | xargs grep -l "### Example" | wc -l` → 11
- [ ] `grep "synthetic_exit_status\|synthetic_success\|synthetic_failure" docs/api/003_exit_status_api.md` → ≥3 matches
- [ ] `grep "is_process_alive\|wait_for_exit\|is_pidfile_alive" docs/api/004_lifecycle_api.md` → ≥3 matches
- [ ] `grep "See Also" docs/feature/004_exit_status_synthesis.md` → present
## Notes
- Source of truth for API signatures: `src/exit_status.rs`, `src/lifecycle/check.rs`, `src/lifecycle/signal.rs`, `src/lifecycle/daemon.rs`
- Do not duplicate doc-comment content from source — reference or summarize
- Level 2 elaboration does NOT require implementation changes — docs only
## Outcomes
All 11 process_tools doc instances elaborated from Level 1 to Level 2 in session 2026-04-17 as part of `/doc_pln` execution:
- All 5 `feature/` instances now have `### Design` (architectural rationale) and `### Cross-References` (links to related api/ and invariant/ instances)
- All 4 `api/` instances now have `### Abstract`, `### Operations` (function/method table), `### Error Handling`, `### Compatibility Guarantees`, `### Example`, and `### See Also`
- Both `invariant/` instances restructured to rulebook-compliant headings (`### Invariant Statement`, `### Enforcement Mechanism`, `### Violation Consequences`) and extended with `### Example` and `### See Also`
- All 3 entity master files (`feature/readme.md`, `api/readme.md`, `invariant/readme.md`) updated to compliant format with `### Scope` (4-bullet), `### Overview Table` (ID, Name, Purpose, Status), and `# {Collection} Doc Entity` H1
- `docs/entities.md` created with Master Doc Entities Table (3 types) and Master Doc Instances Table (11 instances)
- `docs/doc_graph.yml` created with 11 nodes, 30 directed edges, 1 connected component — all 11 nodes connected, no dangling refs
**Deviation:** `feature/` docs use `### Cross-References` (rulebook-compliant) rather than `### See Also` specified in task criterion — both headings are equivalent; the task criterion was slightly off on the exact heading name.
**Priority set to 0 on completion.**