Conciseness

The body is mostly tight operational guidance with no concept-explanation padding, but it includes clear slack: the sentinel-is-the-final-commit rule is stated three times (Invocation Contract, Phase 3f, Notes), the three identical Task() blocks repeat one prompt verbatim, and the Notes section restates points already made (always-3 subagents, foreground parallel, expert-after-subagents). Not a 4 because these redundancies are noticeable rather than minor; not a 2 because there is no explanation of concepts Claude already knows.

Actionability

Fully executable throughout: exact bash commands for commit/sentinel ('git add specs/<feature>/', 'git commit -m "spec-validate: ..."', 'touch specs/<feature>/.validated'), a verbatim copy-paste subagent prompt template, concrete Task() invocations, a complete validation-log.md structure template, and specific discovery commands ('ls .claude/skills/ | grep expert'). Placeholders like <feature> are appropriate parameterization, not pseudocode, so the anchor-5 'copy-paste ready' bar is met.

Workflow Clarity

The sequence is explicit (numbered completion protocol, Phases 1-3 with 3a-3f sub-steps, consensus table, idempotency handling), but the workflow applies batch automated edits across multiple spec files and commits/pushes them with no post-fix verification step — no re-check of the edited spec, no re-validation of the slice DAG after fixes. Per the judging guidelines, missing validation in a batch/destructive operation caps workflow clarity at 3 even though sequencing is otherwise strong (which rules out scores 1-2).

Progressive Disclosure

The skill has no bundle files (references/, scripts/, assets/ all absent) and is a single well-sectioned document (Invocation Contract, Phases, Notes) with clear headers and no nested references, which is appropriate for a ~250-line workflow skill. It is not a 5 because some content that could live one level deep — the impactful/nitpick example taxonomy and the validation-log template — is fully inlined, and no reference files are used to keep the overview lean; not a 3 because structure is good and everything present is clearly signaled.

Specificity

The description lists several concrete actions with explicit artifacts ('Validates a mainspec and its slices via 3-subagent consensus plus expert review, then *applies* impactful fixes directly to the spec files', 'Touches `specs/<feature>/.validated` as its final committed action'), placing it at the several-specific-actions level with only minor coverage gaps (e.g., the validation-log.md output is not mentioned). It is not a 5 because coverage of the full output contract is incomplete, and not a 3 because far more than 1-2 actions are named with concrete paths.

Completeness

The 'what' is clear (validate via consensus plus expert review, apply impactful fixes, touch the sentinel), but the 'when' is entirely absent — there is no 'Use when...' clause or equivalent explicit trigger guidance, which per the judging guidelines caps completeness at 3. It is not a 2 because the 'what' is concrete rather than vague.

Trigger Term Quality

Relevant domain keywords are present ('mainspec', 'slices', 'spec files', 'consensus', 'validation'), but natural phrase variations a user might say ('validate the spec', 'review the spec', 'spec validation', file extensions) are missing and there is no 'Use when...' phrasing. It sits above generic keyword level (2) because the domain terms are the natural vocabulary of this pipeline, but below good coverage (4) because common synonyms are absent.

Distinctiveness Conflict Risk

The description occupies a clear niche in the spec-planning pipeline (mainspec/slice validation with a `.validated` sentinel and no-HITL fix application); its triggers ('mainspec', 'slices', '.validated') are distinct and would not plausibly fire a different skill. Anchor 4's 'minor overlap risk' does not apply — no neighboring skill vocabulary appears.