Conciseness

The body is lean and assumes Claude's competence — no explanation of what investigations or incidents are, and directives like "Do not infer customer impact from an error or alert alone" and "Do not state that no related incident exists because you do not have complete incident history" each earn their tokens. Only the opening sentence mildly restates the frontmatter description, which does not rise to the anchor-4 "minor instances that could be trimmed".

Actionability

Concrete, specific guidance throughout: "generate 2-4 plausible root-cause hypotheses" with required fields, named tools ("Call evidence_record, evidence_remove, and evidence_list"), "Recommend 1-4 concrete actions", and a defined output shape. Not 5 because key steps delegate to external dependencies ("Use the hypothesis-validation skill", "Follow the Evidence rules in the agent instructions") with no inline fallback or example.

Workflow Clarity

A clear 5-phase numbered sequence (understand → hypothesize → validate → assess impact → next steps) with a per-hypothesis checkpoint ("determine whether it is validated, invalidated, or inconclusive") and a prescribed result structure. Not 5 because explicit error-recovery loops (e.g. what to do when a hypothesis is inconclusive or evidence conflicts) are not spelled out.

Progressive Disclosure

No bundle files exist and none are needed: the body is one cohesive, well-sectioned procedure (Procedure / Result / Boundaries) with no inline reference material that belongs in a separate file, and references to other skills are clearly signaled rather than buried. This matches the well-organized, self-contained top anchor.

Specificity

"determine what happened, assess its impact, and recommend next steps using a hypothesis-backed approach" lists several distinct concrete actions with only minor gaps. Not 5 because "operational problem" keeps the domain generic and no further capabilities are enumerated; not 3 because it goes well beyond naming 1-2 actions.

Completeness

The "what" is clearly stated (investigate, assess impact, recommend next steps), but there is no "Use when..." clause or equivalent explicit trigger guidance, which caps completeness at 3 per the rubric guidelines. Not 4 because the "when" is entirely absent rather than merely imprecise.

Trigger Term Quality

Natural phrases like "Investigate", "what happened", "impact", and "next steps" are present, giving good keyword coverage. Not 5 because the most common domain synonyms users would say — "incident", "outage", "root cause", "postmortem" — are missing; not 3 because coverage is clearly more than "some relevant keywords".

Distinctiveness Conflict Risk

The "hypothesis-backed approach" framing and the what-happened/impact/next-steps triad make it mostly distinct from generic debugging or analysis skills. Not 5 because "investigate an operational problem" is broad enough to overlap with incident-response and triage skills; not 3 because the framing is more distinctive than "works with document files".