Conciseness

The body is lean and assumes competence: no git or markdown concepts are explained, the bash block in Step 1 is pure executable commands, and even guidance is compressed to rules like "Never guess the branch name or the base." Every section (prerequisites, four steps, template, rules table, validation checklist) earns its tokens — there is no padding to trim, matching anchor 5 rather than anchor 4's 'minor instances of over-explanation'.

Actionability

Step 1 gives a copy-paste bash block (BRANCH/BASE resolution, diff, log, plan.md and checks.run.log reads), Step 4 gives a concrete deliverable rule, the Template is a fill-in-ready document with ISO 8601 example, and the rules table converts each section into an enforceable rule. This matches anchor 5's 'fully executable; copy-paste ready... specific examples cover the common cases', including a filled example diagram and a wrong/right assumption pair.

Workflow Clarity

A clear four-step sequence (gather facts → list assumptions → check guardrails → write and present) is gated by explicit prerequisites and closed by a six-item validation checklist, with error paths handled: out-of-bounds files go to the "Out of bounds:" line with a reason, and a FAIL sentinel requires "the user's approval to ship". This matches anchor 5's explicit validation, error-handling guidance, and checklist; anchor 4 would imply missing checkpoints, of which there are none.

Progressive Disclosure

The skill is a single-purpose artifact writer with no bundle files; nothing in the ~128-line body belongs in a separate reference (the template is needed on every invocation, so inlining is the correct placement), and navigation is easy via a Contents TOC and consistent section headers. Under the rubric's simple-skill guidance this well-organized single-file structure merits 5; anchor 4 would require organization gaps or misplaced content, which are absent.

Specificity

"Writes `.agent/{branch}/walkthrough.md`, a one-page post-hoc review of finished work — what changed, what was assumed, and the evidence" names the exact artifact, its size, its contents, and its audience. It matches anchor 4 rather than 5 because the description covers a single write action (with minor gaps, e.g. how evidence is sourced) rather than the multiple concrete actions anchor 5 calls for.

Completeness

The 'what' is explicit ("a one-page post-hoc review of finished work — what changed, what was assumed, and the evidence") and the 'when' is explicit with concrete trigger phrases ("Use at Phase 6 before the draft PR; triggers on create walkthrough, generate walkthrough, write walkthrough artifact"), matching anchor 5 exactly. A 4 would require the 'when' to be less explicit than these verbatim triggers; a lower score is ruled out by the presence of an explicit 'Use at' clause.

Trigger Term Quality

"triggers on create walkthrough, generate walkthrough, write walkthrough artifact" gives three natural verb phrases a user would plausibly say, plus the artifact path itself. It falls short of anchor 5's comprehensive synonym coverage only in that adjacent phrasings like "review summary" or "change summary" are absent, placing it squarely at anchor 4.

Distinctiveness Conflict Risk

The walkthrough artifact is a clear niche ("a one-page post-hoc review of finished work... for the reviewer to read after the fact") with distinct, specific triggers ("create walkthrough, generate walkthrough, write walkthrough artifact") that no similar skill would claim, matching anchor 5. Anchor 4 would require some overlap with closely related skills, which the uniquely named artifact and trigger set avoid.