Conciseness

The body is dense and skill-specific — prerequisites, a six-step procedure, a worked example, a runnable helper, and limitations — with no tutorials on concepts Claude already knows. Not a 5 because the changelog line "Modified by AAS maintainers on 2026-09-05 to remove unsupported benchmark claims..." is time-sensitive editorial metadata that earns no operational value, and several procedure sentences carry stacked caveats that could be tightened.

Actionability

Guidance is fully executable: concrete harness-validation actions ("Run a known-pass case, a known-fail case and a deliberate verifier/infrastructure failure"), a copy-paste-ready wilson95 function with input validation, expected output checks ("0/10 has a positive upper bound; 10/10 has a lower bound below 1; 0/0 fails"), and a worked example with exact expected output format. Common cases are covered concretely, matching the anchor-5 example.

Workflow Clarity

The six numbered steps give a clear sequence with explicit validation checkpoints and feedback loops: step 2 validates the harness before measurement and says to "fix the harness and repeat these checks", and step 6 prescribes "Make a bounded fix, rerun the failing case to verify the mechanism, then rerun the applicable frozen regression suite from clean state". This matches anchor 5's validate-fix-retry pattern; the destructive/batch validation cap does not apply because validation is thoroughly present.

Progressive Disclosure

SKILL.md is a clear overview; the single bundle file references/architecture-sketches.md is one level deep, explicitly gated ("Read the corresponding section... only when designing a custom harness"), and each of the five bullet links targets a real, verified heading in that file. Content is appropriately split with easy navigation, matching the anchor-5 example.

Specificity

"Evaluate agent behavior with versioned cases and explicit verifiers" plus "comparing agent or prompt changes, reproducing failures, or running agent regression tests" lists several concrete capabilities (versioned case sets, explicit verifiers, regression testing, failure reproduction). Not a 5 because the core action "evaluate agent behavior" is somewhat abstract and coverage of what evaluation produces (reports, decisions) is only implied.

Completeness

Both questions are explicitly answered: the what ("Evaluate agent behavior with versioned cases and explicit verifiers") and the when ("Use when comparing agent or prompt changes, reproducing failures, or running agent regression tests") with three concrete trigger phrases. This matches the anchor-5 example structure (capability statement followed by explicit 'Use when...' triggers) and is not a 4, where the 'when' would be less specific.

Trigger Term Quality

Natural phrases a user would say include "comparing agent or prompt changes", "reproducing failures", and "agent regression tests" — good keyword coverage. Not a 5 because common synonyms like "eval", "A/B testing", "benchmark comparison", or "flaky test" are absent, leaving a few natural entry points uncovered.

Distinctiveness Conflict Risk

"Agent regression tests", "versioned cases", and "explicit verifiers" carve a clear niche that would rarely mis-trigger against unrelated skills. Not a 5 because the fairly broad term "agent behavior" leaves minor overlap risk with adjacent skills like general test-writing or benchmarking skills.