Conciseness

The body is ~28 lines with zero padding: no git/Linear/GitHub concepts are explained ("Fetch the issue with the Linear or GitHub tools" assumes competence), and constraints are stated as tight imperatives ("At most 400 words", "Stop here if the diff is empty"). Every sentence instructs. This matches the 'lean and efficient; every token earns its place' anchor. Not 4: there are no over-explanations to trim.

Actionability

Concrete commands are given verbatim ("git diff <fixed-point>...HEAD", "git log --oneline <fixed-point>..HEAD", "Confirm it with git rev-parse"), discovery patterns are specified ("a Linear key (SB-1234) or Closes #N"), and both subagent briefs are quoted copy-paste ready with word limits. The output format is fully determined ("## Standards" / "## Spec", one summary line per axis). Per the rubric's instruction-skill note, absence of code is not penalized when guidance is this actionable. Not 4: no gaps — even the empty-diff and no-spec edge cases have prescribed outcomes.

Workflow Clarity

Five numbered, strictly ordered steps with explicit checkpoints: "Confirm it with git rev-parse", "Stop here if the diff is empty", a fallback chain for spec discovery (spec file → tracker key → PR body → "no spec"), and a termination condition ("Done when both axes have reported, or the Spec axis has reported 'no spec'"). The workflow is read-only, so the destructive/batch validation cap does not apply. Not 4: validation and exit conditions are explicit at every decision point, not mostly present.

Progressive Disclosure

The body itself is well organized (under 50 lines, clear sections) and its single reference is clearly signaled and one level deep: "Both follow the [review rules](./rules.md)", "the section 'Edge cases and guards' from [the review rules](./rules.md), pasted in full". However, no bundle directories (references/, scripts/, assets/) exist and rules.md is absent from the bundle, so the skill's central reference — whose content step 4 depends on — dead-ends. Not 4: a missing referenced file is more than a 'minor organization gap'; not 2: the reference is clearly signaled, not buried, and nothing is wrongly inlined.

Specificity

Quotes: "Reviews the changes since a fixed point (commit, branch or merge-base) on two axes, in parallel subagents", "Standards: does the code follow this repo's guidelines?", "Spec: does it do what the issue asked?" — multiple concrete, distinct actions (diff-since-fixed-point review, standards check, spec check) plus the execution mechanism, comprehensively covering the skill's scope. Not 4: anchor 4 tolerates 'minor gaps in coverage', and no capability of the skill is left unmentioned. Third-person voice, so no voice penalty applies.

Completeness

The 'what' is explicit ("Reviews the changes since a fixed point ... on two axes, in parallel subagents", with both axes defined) and the 'when' is explicit with concrete trigger phrases ("Use when the user asks to review a branch, a PR or work in progress, or to 'review since X'"). This clearly matches the anchor 5 example's structure of what + when with concrete triggers. Not 4: the 'when' clause is already fully explicit and specific, not merely present.

Trigger Term Quality

Quotes: "review a branch, a PR or work in progress", "to 'review since X'" — several natural phrasings users would actually say, including a quoted verbatim trigger. Not 5: common synonyms like "code review", "review my changes" or "review the diff" are missing. Not 3: coverage goes well beyond 'some relevant keywords' with multiple natural user phrasings.

Distinctiveness Conflict Risk

Quotes: "since a fixed point (commit, branch or merge-base)", "Standards", "Spec", "review since X" — a clearly carved niche with distinctive framing. Not 5: triggers like "review a PR" are shared with generic code-review skills, leaving minor overlap risk with closely related skills. Not 3: the two-axis, fixed-point framing is far more specific than 'somewhat specific'.