Conciseness

The ~30-line body never explains concepts Claude already knows; every line instructs ("Write one test for one behavior... use the real code, not mocks"; "Add nothing the test does not need"). Lean and efficient with every token earning its place; not 4 because there is no over-explanation left to trim.

Actionability

Steps are specific and directive ("The test must fail because the behavior is missing, not because of a typo or a missing import"), and test-writing detail is concretely delegated to the reference file. However, "Run the project's test command" gives no concrete command or way to find one — mostly executable guidance with a minor gap; matches 4, not 5 (nothing is copy-paste ready).

Workflow Clarity

The five-step Red/Green/Refactor sequence has explicit validation checkpoints ("Watch it fail", "Watch it pass", "Run the suite again"), a feedback loop for error recovery ("If it passes, it tests nothing new: change the test"), and a final checklist ("Before you report the work as done"). Matches the 5 anchor exactly; not 4 because checkpoints and recovery are explicit rather than implicit.

Progressive Disclosure

The body is a concise, well-sectioned overview with a single clearly signaled, one-level-deep reference — "When writing or changing a test, read references/writing-good-tests.md" — and the bundle confirms that file exists (198 lines) with no nested references inside it. Not 4: navigation is unambiguous and nothing that belongs in the reference is inlined.

Specificity

The description lists four concrete, sequenced actions — "write one failing test, run it and watch it fail, write the minimal code to pass, then refactor with the tests green" — comprehensively covering the entire red-green-refactor workflow. Not 4: there are no minor gaps in the action coverage.

Completeness

"Implements a feature or bug fix test-first: write one failing test..." clearly answers what, and "Use when a change alters code behavior: a new feature, a bug fix, or a behavior change" explicitly answers when with concrete trigger phrases. Not 4: the when-clause is explicit and specific, not merely present.

Trigger Term Quality

Natural trigger terms are present ("a new feature, a bug fix, or a behavior change"), but common synonyms users would say — "TDD", "test-driven", "unit test" — are absent, and "delivery-flow" is internal jargon no user would naturally say. Matches the 4 anchor (good coverage, a few natural terms missing); not 5 because synonym coverage is not comprehensive.

Distinctiveness Conflict Risk

The test-first methodology ("write one failing test", "refactor with the tests green") carves a clear niche, but the when-clause ("a new feature, a bug fix, or a behavior change") matches nearly any code change, creating minor overlap risk with general development-workflow skills. Mostly distinct with minor overlap — matches 4; not 5 because the trigger conditions are broad.