Conciseness

The body is directive throughout ("Read the error completely", "Reproduce the bug", "Never guess - Evidence first") and never explains concepts Claude already knows, but minor trimming is possible: the final "Output" banner template and the "Rules" section partially restate the per-phase BLOCKED gates and the Anti-Rationalization table.

Actionability

Concrete, copy-paste-ready commands are provided ("git log --oneline -10", "git diff HEAD~3", "grep -r \"error message\" .", "git add -A && git commit -m \"fix: [description]\"", "git tag checkpoint/bugfix-[name]") alongside numbered steps per phase; minor gaps remain, e.g. "Execute minimal test" gives no example of what such a test looks like.

Workflow Clarity

Four phases are explicitly sequenced with hard validation gates ("BLOCKED until evidence collected", "BLOCKED until patterns identified", "BLOCKED until hypotheses formulated"), explicit feedback loops ("If rejected: Test next hypothesis"), error recovery via the Three-Strike Rule, and verification steps ("Verify test passes", "Reproduction test: PASS").

Progressive Disclosure

A single self-contained file with well-organized sections (Phases, Workflow, Three-Strike Rule, Output, Anti-Rationalization, Rules) and no external references — appropriately so, since no detail here needs a separate file — though at ~210 lines a few inline per-phase output templates could be tightened to make the overview leaner.

Specificity

The description names the domain ("any bug, test failure, unexpected behavior, or error") but contains no concrete capability actions — phrases like "before proposing fixes" only imply what the skill does, never stating it (e.g. systematic 4-phase debugging). This matches 'names the domain but actions are minimal or generic' rather than score 3, which requires 1-2 named actions.

Completeness

The 'when' is explicit and strong ("Use when encountering...", "Use especially when previous fix attempts have failed") but the 'what' is entirely absent — the description never says what the skill actually does. This exactly matches anchor 2 ('only when is present without what', e.g. 'Use when working with documents'); it cannot be 3-4 because those require at least a clear 'what'.

Trigger Term Quality

Good natural coverage with "bug", "test failure", "unexpected behavior", and "error" — phrases users genuinely say — plus the distinctive "previous fix attempts have failed". Not score 5 because common synonyms like crash, exception, traceback, or regression are missing; clearly above score 3's 'missing common variations'.

Distinctiveness Conflict Risk

The debugging niche is somewhat specific ("bug", "previous fix attempts have failed" is distinctive), but the sweeping triggers "any... error" and "unexpected behavior" would fire on nearly every technical conversation and overlap with testing or error-handling skills — matching 'somewhat specific but could still overlap with similar skills' rather than the minor-overlap profile of score 4.