Conciseness

Efficient and dense — signal table, pattern table, ordered rules, output template — with only minor over-explanation that could be trimmed (the Google 84% motivation paragraph, the fault/defect/error terminology Claude largely knows, and the ISTQB-404 aside), placing it just below the every-token-earns-its-place anchor.

Actionability

Fully concrete guidance throughout: exact match strings (SIGSEGV, ENOENT, strict mode violation), conjunctive first-match-wins rule conditions, a fixed copy-paste verdict template, and explicit conventions to state (windows used, N threshold). As an instruction-only skill its guidance is fully actionable without code.

Workflow Clarity

Clear three-step sequence (extract signals → walk rules in order → emit verdict) with explicit checkpoints: all seven signals recorded before any rule, confidence gated on signal availability, the missing-vs-negative-signal distinction, and the mandatory Not-classified-as audit block. The operation is read-only classification, so the destructive/batch validation cap does not apply.

Progressive Disclosure

Well-signaled one-level-deep references to real files — the worked example and anti-pattern catalogue each get a link plus a one-line description of their contents — while the core method stays inline. Content is appropriately split and easy to navigate.

Specificity

Lists multiple concrete actions covering the full capability pipeline — "Extracts seven failure signals from the runner output, stack trace, run history, and environment metadata", "walks an ordered first-match-wins rule set to exactly one verdict", "Emits the verdict together with the alternatives that were rejected" — in third person, with no coverage gaps, matching the comprehensive-coverage anchor.

Completeness

Explicitly answers both questions: the what (classify a red CI test into one of six named verdicts with rejected alternatives recorded) and the when ("Use when a test has just gone red and the next action depends on whether the cause is a product defect, a non-deterministic test, or drifted infrastructure") with concrete trigger phrases.

Trigger Term Quality

Good natural-term coverage — "red CI test", "a test has just gone red", "flaky", "non-deterministic test", "product defect", "drifted infrastructure", "stack trace" — but common user phrasings like "intermittent failure", "failing test", or "is this a flake" are absent, so it falls short of the comprehensive-synonyms anchor at 5.

Distinctiveness Conflict Risk

Clear niche — pre-fix failure classification — with distinct triggers, and it explicitly delimits itself from adjacent work ("before anyone starts fixing it", classification not report-writing or remediation), minimizing conflict risk with general debugging or bug-report skills.