Conciseness

The body is dense with non-obvious, actionable guidance and teaches no basic concepts (no 'what a stack trace is' padding), but it carries motivational over-explanation that could be trimmed — e.g. 'This skill exists to prevent that', 'A plausible-looking fix applied to an unverified cause is worse than no fix — it masks symptoms, burns trust', and the prime-directive section restating the evidence-first rule that Core Principles then repeats. That is the anchor-4 profile: efficient with minor instances of over-explanation, not the every-token-earns-its-place anchor 5.

Actionability

Guidance is fully concrete for an instruction-only skill: specific commands and tools per situation ('git bisect', 'EXPLAIN ANALYZE', 'kubectl describe', 'docker logs'), explicit per-artifact first moves ('read the lines before the error', 'find the first frame in our code'), a complete worked example carrying an end-to-end investigation, and a copy-paste output template with a concrete confidence rubric. Specific examples cover the common cases, matching anchor 5.

Workflow Clarity

The eight phases are explicitly sequenced with phases 1–4 marked mandatory and 5–7 gated by bug domain, and the workflow has explicit validation gates and feedback loops: 'Never propose a code change until the evidence identifies the cause', hypotheses ranked with the cheapest way to confirm or kill each, 'If the top hypothesis is only MEDIUM, the honest deliverable is ... the one check that would confirm it', and Phase 4 requiring why the other hypotheses are ruled out. This matches the anchor-5 checklist-with-explicit-validation-and-recovery pattern; anchor 4's 'minor validation gaps' does not apply.

Progressive Disclosure

Structure is good: a 'Read | When' reference map, on-demand loading instructions ('read the reference file when its phase begins'), and all 8 references/*.md files exist and link only one level deep (sibling cross-references, no nesting chains). The gap: the body's 'Required packaged policies' section links 9 shared/base/*.md files plus shared/workflow-contract.md, none of which exist in the bundle — 10 dead reference paths — which is more than a trivial organization issue and keeps this below anchor 5's 'easy navigation'.

Specificity

The description names the domain concretely ('active, observable software failure, error, regression, or unexpected behavior') and specifies the method ('using reproduction and evidence') plus the action pair 'Investigate and safely fix'. It lists several specific elements but the action vocabulary is limited to investigate/fix, leaving minor gaps versus the comprehensive multi-action anchor 5.

Completeness

Both 'what' ('Investigate and safely fix an active, observable software failure... using reproduction and evidence') and 'when' ('Use for the proximate technical cause and remediation. Do not use for a systemic incident postmortem or general performance tuning') are explicitly present, and the do-not-use clause adds useful disambiguation. The when-clause is framed abstractly ('proximate technical cause and remediation') instead of concrete user situations like 'use when the user reports a bug, crash, or failing test', so it sits at anchor 4 rather than the concrete-trigger-phrases anchor 5.

Trigger Term Quality

Natural user-facing terms like 'failure', 'error', 'regression', 'unexpected behavior', and 'fix' are present, giving good keyword coverage. A few of the most common phrases a user would actually say — 'bug', 'crash', 'failing test', 'broken' — are missing, which is exactly the anchor-4 condition ('a few natural terms missing') rather than the comprehensive synonym coverage of anchor 5.

Distinctiveness Conflict Risk

The scope is narrowed to 'active, observable' failures and the explicit 'Do not use for a systemic incident postmortem or general performance tuning without a failure' clause cleanly separates this from adjacent skills (root-cause-analysis, performance-optimization). This is a clear niche with distinct triggers and minimal conflict risk, matching anchor 5.