Conciseness

The body is efficient — tables, numbered steps, and templates with no padding explaining concepts Claude already knows. Minor over-explanation remains (the "Your job is not to run a single check" framing and the wordy "Suggest Verification After Implementation" section), so it is not the lean 5 anchor.

Actionability

Guidance is mostly executable: specific commands ("vercel logs", "vercel env ls", check ".env.local", scan "package.json" scripts), a copy-paste report template, and a concrete common-breaks checklist ("Missing `await`", "Wrong HTTP method (GET handler but POST fetch)"). Browser-side checks are delegated to `agent-browser` without exact commands, and a few steps stay directional, keeping it below the fully-executable 5 anchor.

Workflow Clarity

A clear four-step sequence with explicit validation checkpoints ("Report what you find at each layer before proceeding", the Evidence-baseline table), feedback loops for error recovery (stop conditions, "Do not run the same check more than twice", stop at the first broken boundary), and checklists (common breaks, flow status report). Checkpoints and loops are fully explicit, exceeding the 4 anchor.

Progressive Disclosure

The single-file body is well-organized into clear sections (trigger conditions, four steps, stop conditions, report template, coordination) with no bundle files needed. The coordination section names other skills (`investigation-mode`, `observability`, `agent-browser-verify`) without paths or navigation, so it falls just short of the 5 anchor's clean reference structure.

Specificity

Concrete actions are stated — "infers what the user is building, then verifies the complete flow end-to-end" — with the layer chain "browser → API → data → response" adding concrete scope. It lists two core actions rather than the multiple-action comprehensive coverage of the 5 anchor.

Completeness

Both questions are answered explicitly: what ("infers what the user is building, then verifies the complete flow end-to-end: browser → API → data → response") and when ("Triggers on dev server start and 'why isn't this working' signals") with concrete trigger phrases. The 'when' is explicit and specific, so the 4 anchor's caveat does not apply.

Trigger Term Quality

Natural trigger phrases are present ("dev server start", "'why isn't this working' signals", "end-to-end"), matching the good-coverage anchor. Common variants a user would naturally say — "verify the flow", "check everything works", "does it actually work" — are missing, so it falls short of the comprehensive 5 anchor.

Distinctiveness Conflict Risk

"Full-story verification" of the complete flow "browser → API → data → response" carves a distinct niche with dev-server triggers. Minor overlap risk remains: the "why isn't this working" signal could also match general debugging skills, so it is not the minimal-conflict 5 anchor.