Conciseness

The body is dense, assumes competence, and never explains basics Claude already knows, but there is measurable redundancy: the "What matters" principles are restated across sections 1, 6, and "Tone", and lines like "The gap between your model and theirs exposes anchoring in both directions" are framing rather than instruction. Not score 5 (every token does not earn its place) and not score 3 (there is no unnecessary explanation or padding of known concepts).

Actionability

For an instruction-only skill the guidance is fully actionable: an exact record path (`.mastracode/scratch/issues/<owner>-<repo>-<n>.md`), a closed verdict taxonomy with literal strings, branch-name patterns to infer the issue, per-branch deeper checks, and executable commands one level deep in `references/recipes.md` pointed to at each step. Not score 4 because there are no minor gaps — the common cases (resolve issue, trace symptom, history, regression, probe, posting) are all covered concretely.

Workflow Clarity

A clear six-step sequence (build model → read thread → diagnose → history → verify → decide and brief) with explicit validation checkpoints: falsification-based verification, "Never claim a reproduction you did not run", an approval gate for posting ("Show the draft; wait for the go"), and a re-investigation loop. The destructive/outward-facing operation (GitHub posting) has validation, so no cap applies.

Progressive Disclosure

The body is an overview and all executable detail lives one level deep in the existing `references/recipes.md` and `references/templates.md`, each clearly signaled at the exact point of use ("Resolve the issue with the minimal recipe in `references/recipes.md`", "Use `references/templates.md` as an example, not a schema"). Not score 4 because there is no inline content that should have been split out and navigation is unambiguous.

Specificity

Multiple concrete actions are listed — "form an independent model before reading the thread's theories, trace the mechanism and history, verify the diagnosis, and return a concise briefing with a verdict and fix direction" — comprehensively covering the investigation workflow. It is not score 4 because coverage is comprehensive rather than having minor gaps; not below 5 since no action is vague.

Completeness

Both what ("Investigate a GitHub issue or reported bug... trace the mechanism and history, verify the diagnosis, and return a concise briefing with a verdict and fix direction") and when ("Use for triage, root-cause analysis, or re-investigation") are explicitly and clearly stated. Score 4 would require the when to be less explicit; here concrete trigger phrases are present.

Trigger Term Quality

Good natural keywords: "GitHub issue", "reported bug", "triage", "root-cause analysis", "re-investigation" — phrases users would actually say. It is not 5 because common synonyms like "diagnose", "debug", or "dig into this issue" are absent, but well above anchor 3 since multiple natural trigger phrases are present.

Distinctiveness Conflict Risk

The niche is clear — maintainer-style GitHub issue investigation with a verdict — and triggers like "triage" and "root-cause analysis" are distinct. Minor overlap risk remains with generic debugging and PR-review skills triggered by "reported bug"; it is not 5, but far more distinct than the "somewhat specific" anchor 3.