Conciseness

Mostly efficient — the body encodes non-obvious, skill-specific policy (frozen-context semantics, evidence budgets, classification rules) rather than concepts Claude already knows — but it could be tightened: the boundary-only mode is restated roughly three times ("With `mode: boundary-only`, produce **Insufficient evidence**...", "For `boundary-only`, proceed directly to the single report after that read", "For `boundary-only`, proceed to `add_comment` after this read"), and section 1's ~120 lines of conditional rules sprawl with run-on sentences. This is anchor 3 (mostly efficient but could be tightened) rather than anchor 4 (only minor trimming needed), because the repetition and density go beyond minor instances.

Actionability

Fully executable guidance: a concrete jq command with a known schema for the first read, a PowerShell collector snippet, a classification table specifying the exact required evidence per verdict, and a copy-paste-ready markdown report template with explicit placeholder-substitution instructions. Anchor 5: specific examples cover the common cases.

Workflow Clarity

A clearly sequenced four-phase workflow (establish boundaries → trace implementation with 5 numbered sub-steps → calibrate conclusion → write report) with explicit validation checkpoints ("Verify the candidate change is present in the bad revision and absent from the good one") and error-recovery feedback ("If the source interval does not explain the symptom, inspect relevant dependency version changes... Stop with an evidence gap"). Not anchor 5 because several checkpoints and mode-handling rules are buried in dense prose rather than surfaced as a checklist, leaving minor gaps in explicitness.

Progressive Disclosure

Sections are well-organized with numbered phases, but this is a ~310-line monolith with no bundle files: the ~120 lines of field-by-field frozen-context semantics in section 1 and the full report template in section 4 are inlined content that clearly belongs in separate reference files. Anchor 3 (some structure, but content that should be separate is inline) rather than anchor 4, since there are no references at all to signal.

Specificity

"Trace a reported dotnet/maui issue to the commit or PR that introduced its regression using release boundaries, source history, and linked evidence" and "Distinguish confirmed introductions from likely candidates and missing evidence" list multiple concrete actions with the methods named, comprehensively covering the skill's scope. It matches the anchor-5 example's coverage level, not anchor 4, which allows minor gaps in coverage.

Completeness

The first sentence explicitly answers "what" (traces an issue to the introducing commit/PR using release boundaries, source history, and linked evidence) and the "Use for ..." clause explicitly answers "when" with three concrete trigger phrases — the anchor-5 pattern. The "when" clause is explicit with concrete triggers, so this is not the anchor-4 case where the trigger guidance could be more specific.

Trigger Term Quality

Explicit natural trigger phrases — "Use for "/issue trace-regression", "which PR introduced this issue", or "trace this regression"" — are exactly the phrasings a user would say, covering the command form, the natural question form, and the imperative form. This is comprehensive natural-term coverage per anchor 5, beyond anchor 4's "a few natural terms missing".

Distinctiveness Conflict Risk

A clear niche (dotnet/maui regression introduction tracing) with distinct triggers, plus explicit negative scoping ("not PR regression-risk review, CI failure triage, or automatic bug fixing") that disambiguates the nearest competing skills. Minimal conflict risk; anchor 5 rather than anchor 4, which still admits overlap with closely related skills.