Dense, policy-oriented body with minimal padding ('Single infrastructure retry per test run; if it fails twice, it is not flake') that assumes Claude's competence and avoids explaining concepts Claude already knows.

Provides concrete, copy-paste-ready templates (Test Strategy, Test Matrix table, Implementation Plan) and specific rules (case ID scheme '{CATEGORY}-{NN}', 'max 3 retries with exponential backoff', 'Target: under 5 minutes') rather than vague direction.

Includes a sequenced ## Workflow section and numbered Preflight checks acting as validation checkpoints before risky e2e runs, plus feedback loops (retry-failure diagnostics, flake classification before fix).

A self-contained single file with no external references and no bundle files, well-organized under clear headers; per the guidelines this warrants a 3 for skills needing no external references.

Enumerates multiple concrete capability axes ('Test layering, execution, and CI guidance across unit, integration, and e2e') rather than naming only a domain, matching the 'lists multiple specific concrete actions' anchor.

Clearly answers both what (test layering/execution/CI guidance) and when via an explicit 'Use when...' clause with concrete triggers.

'designing tests, writing test cases, or planning test strategy' are natural phrasings a user would say, giving good coverage of relevant trigger terms.

Targets a specific niche (test strategy/matrix/CI for modules) with triggers unlikely to fire for unrelated skills, though 'testing' is a broad domain that could lightly overlap similar skills.