Conciseness

The body is lean with no padding and assumes competence, but the "Output" and "Completion" sections duplicate report-specification content ("Validation status summary" vs "pass/partial/fail conclusion"; "Deviations and risks" vs "Blocking issues"). Anchor 4's "minor instances that could be trimmed" fits; not 5 because of this redundancy.

Actionability

Concrete, specific steps for an instruction-only skill ("Extract expected file changes, phase outcomes, and success criteria", "Run plan-defined automated checks"), so absent code is not penalized. Not 5 because "Gather implementation evidence from code and history" leaves the how (e.g., git diff/log) unspecified; well above anchor 3's pseudocode-level guidance.

Workflow Clarity

A clear 5-step sequence with explicit validation steps (run automated checks, compare expected vs actual per phase), an end-of-run feedback loop ("Smallest next corrective action"), and a checklist ("Manual verification checklist") — matching anchor 5. It is a read-only validation skill, so the destructive/batch cap does not apply, and anchor 4's "minor validation gaps" is not present.

Progressive Disclosure

The skill is under 50 lines, needs no external references (none exist in the bundle), and is organized into clearly headed sections (Workflow, Validation Focus, Output, Completion). Per the simple-skill guideline this earns anchor 5 on well-organized sections alone.

Specificity

Names the domain and several concrete actions ("verify completion", "compare code changes to a plan", "produce a validation report") with only minor gaps. It falls short of anchor 5 because "executed correctly" leaves the specific validation dimensions unspecified, and is well above anchor 3's 1-2 actions.

Completeness

Explicitly answers both what ("Validate that an implementation plan was executed correctly") and when ("Use when the user asks to verify completion, compare code changes to a plan, or produce a validation report") with three concrete trigger phrases. This matches the anchor-5 example pattern; the when-clause is explicit and specific, so anchor 4's "could be more explicit" does not apply.

Trigger Term Quality

The trigger phrases "verify completion", "compare code changes to a plan", and "produce a validation report" are natural user phrasings with good coverage. Not 5 because common synonyms like "audit", "check the plan", or "review against the plan" are missing; clearly better than anchor 3's partial coverage.

Distinctiveness Conflict Risk

A clear niche (plan-execution validation) with distinct triggers, but "compare code changes to a plan" carries minor overlap risk with code-review skills. Mostly distinct per anchor 4; not 5 because a closely related review/verification skill could still compete for the same phrasing.