Lean for its complexity: compact Haskell Spec, decision tables, and exact wording blocks assume Claude's competence (e.g. "SKILL.md is prompt-as-code — its quality is measured by behavior, recoverability, and testability, not by length") with no padding explaining basic concepts; ~290 lines but each section earns its place.

Fully concrete guidance: typed Spec functions, exact labels ("minimal hardening patch", "full protocol refactor"), real paths ("experiments/<skill>-routing-001/fixtures/routing/*.json"), runnable checks ("git diff --check"), and an Output Contract enumerating required final-response fields.

A 12-step numbered workflow with explicit validation gates ("Apply the Regression Ladder and Live Host Safety Gate"), feedback loops ("triage failures in this order before blaming the skill", "cap live wording fixes at two rounds"), and safety bounds for destructive/batch host operations — so the destructive-operations cap does not apply.

A References section signals each file with a "read when..." trigger, mandates "must not load all references at startup", and the three cited paths (cs-skill-spec-standard.md, cs-skill-quality-gates.md, cs-skill-fixture-patterns.md) all exist in the bundle — well-organized one-level-deep disclosure.

Lists multiple concrete actions — "creating, refactoring, simplifying, or reviewing cs-* skills" and "classify the skill, define Spec/types/state machine, separate operator rules from references, add machine-checkable contracts, and design decision fixtures" — rather than naming only a domain.

Explicitly answers both: what ("Applies the prompt-as-code framework: classify the skill, define Spec/types/state machine...") and when ("Use when creating, refactoring, simplifying, or reviewing cs-* skills under plugins/codestable/skills or .claude/skills").

Natural trigger verbs for the niche ("creating, refactoring, simplifying, or reviewing") plus the concrete noun "cs-* skills"; it would not score below 2 since coverage of what a user would say is strong, and the jargon ("prompt-as-code framework") sits in the what-clause, not the trigger.

Clear niche with explicit disambiguation — "Do not use for normal feature implementation; use cs-feat/cs-issue/cs-docs for product work and eval-cs-skill for full measured experiment loops" — making conflicts with sibling skills unlikely.