Conciseness

The body is ~85 lines of pure instruction with dense tables ("| `AGENTS.md` | the pitch, tech stack, 30-second architecture... | rationale, full specs |") and zero explanation of concepts Claude already knows; even the opening triad ("Every project area has one stable home") states layout invariants in three short sentences rather than padding.

Actionability

Instruction-only but fully concrete: explicit file ordering ("Write `invariants.md` first... and `AGENTS.md` last"), an executable lint command ("Run `prose-lint.py` on `AGENTS.md` and every file under `docs/`"), testable rules ("An internal name in a spec... is a defect"), and measurable size budgets ("`AGENTS.md` at most about 150 lines, each feature spec 5 to 15 items of 1 to 3 sentences").

Workflow Clarity

A clearly sequenced 5-step workflow with explicit validation (step 5: lint and "fix every finding", backed by the Definition-of-Done item "prose-lint.py reports no findings"), two user-confirmation checkpoints (steps 2 and 5), and an evidence-based checklist — the validate-fix loop for this batch file-creation skill is specified, matching the anchor-5 pattern.

Progressive Disclosure

The body is a true overview that delegates writing rules ("../../assets/writing.md"), skeletons ("templates/"), the spec format ("templates/product-specs-README.md"), and linting ("scripts/prose-lint.py") to clearly signaled, one-level-deep references with a "Read at" timing column; nothing that belongs in a separate file is inlined. Note: the referenced bundle files were not present in the review directory to verify existence, but the written structure fully matches the anchor.

Specificity

"Bootstrap or extend a repo's documentation" plus "Creates AGENTS.md + docs/ structure (architecture, guidelines, product-specs with stable IDs and invariants)" names multiple concrete deliverables covering both the create and extend paths, matching the comprehensive-coverage anchor rather than the minor-gaps anchor at 4.

Completeness

Explicitly answers both questions: the 'what' ("Creates AGENTS.md + docs/ structure... with stable IDs and invariants") and the 'when' ("Use when the user asks to..." with four concrete trigger phrases), mirroring the anchor-5 example structure exactly.

Trigger Term Quality

Four natural quoted phrasings ("set up agent docs", "add AGENTS.md", "create docs/ structure") give good keyword coverage, but the 5 anchor requires comprehensive synonym coverage and common variants like "write documentation", "document the codebase", or "onboarding docs" are missing.

Distinctiveness Conflict Risk

The niche is agent-facing repo documentation with stable spec IDs, and triggers like "add AGENTS.md" and "set up agent docs" are distinct from generic documentation or README-edit requests, giving minimal overlap risk with related skills.