Conciseness

The body assumes Claude's competence — it invokes protobuf, OpenAPI, plan modifiers, and framework schema maps without explaining them — and nearly every clause encodes a distinct requirement ("test both mismatch directions and null members separately", "including values named `empty` or `unknown`"). It fits anchor 5's lean, every-token-earns-its-place standard rather than anchor 4, since there is no over-explanation to trim.

Actionability

Guidance is highly concrete and executable in substance — "If omitted Create fails, first create a valid resource, then remove the field on Update and record the next refresh and plan", "Sort recorded validation diagnostics before comparing them" — but there are no commands or templates: no example test command, no coverage-matrix format, no golden-file example. This matches anchor 4's mostly executable guidance with minor gaps rather than anchor 5's copy-paste-ready coverage, and exceeds anchor 3's pseudocode-level guidance.

Workflow Clarity

A clear five-step sequence (read schema → build coverage matrix → trace omissions → record and compare → verify and open PR) with explicit validation checkpoints ("Compare the coverage matrix with the golden file list. Resolve every missing cell or state why it does not apply"; "Run the baseline tests and review the final diff and fixture content before opening the PR"), a built-in checklist (the coverage matrix), and a conditional recovery path. This matches anchor 5 rather than anchor 4 because the checkpoints and error-recovery branches are explicit, not merely implied.

Progressive Disclosure

The short (~20-line) body is well organized into Trigger, Fix, numbered steps, Diagnostic order, and Why, with one clearly signaled one-level reference. However, that sole reference escapes the skill bundle ("../../../docs/generator-migration-review-rubric.md") and no bundle files exist to verify it against — a minor organization gap that keeps it at anchor 4 rather than anchor 5's clean, well-signaled navigation.

Specificity

Lists several concrete actions — "recording or reviewing" a resource's baseline and "Check schema, writes, reads, and omitted fields" — matching anchor 4's several specific actions with minor gaps; it stops short of anchor 5's comprehensive coverage because the body's import, data-source, and diagnostics checks are absent from the description.

Completeness

Both parts are explicit: the when is "Use when recording or reviewing a handwritten Terraform resource's protocol golden baseline before generator migration" and the what is "Check schema, writes, reads, and omitted fields", with concrete trigger phrases throughout. It is not anchor 4 because the when could not reasonably be more explicit or specific.

Trigger Term Quality

"handwritten Terraform resource", "protocol golden baseline", and "generator migration" are exactly the phrases a practitioner would say, giving good keyword coverage; a few natural variants (e.g., "golden files", "acceptance tests", "provider") are missing, so it fits anchor 4 rather than anchor 5's comprehensive synonym coverage.

Distinctiveness Conflict Risk

The trigger scenario — protocol goldens for a handwritten Terraform resource before generator migration — is a clear niche with distinct terms that would not fire unrelated skills, giving minimal conflict risk as in anchor 5. It is not anchor 4 because there is no realistic overlap with closely related skills given this specificity.