Conciseness

The body is dense and domain-specific — error-taxonomy tables, exact thresholds ("trade_count=0", "capital utilization < 50%", "at most 3 repair iterations") — with only minor trimmable parts: the long benchmark-explanation sentence in Logic Bugs #5 and an Overview that restates the description. It is efficient overall but not lean enough for 5.

Actionability

Concrete file paths ("artifacts/metrics.csv", "code/signal_engine.py"), tool calls (read_file, edit_file), a copy-paste AST validation command, and specific action-item examples make the guidance mostly executable. Some fixes ("Add length checks", "Ensure the return value is pd.Series") are directives without exact code, keeping it just below fully copy-paste ready.

Workflow Clarity

A clear 5-step Diagnostic Workflow with an explicit verify step, a Hard-Gate Checklist, Post-Fix Validation Rules, and a fix-one-issue-then-rerun feedback loop capped at 3 iterations. This matches the top anchor: explicit validation steps, error-recovery loops, and a checklist for a complex process.

Progressive Disclosure

The ~88-line body is well organized with headers, tables, and a one-level-deep cross-skill pointer ("See the strategy-discovery skill"), and no bundle files exist to reference. It sits above 50 lines with some inline detail (benchmark fallback rules, evidence hookup) that could live in a reference file, so structure is good but not the ideal split of 5.

Specificity

"Diagnose failed or underperforming backtests, locate the root cause, and fix the issue" lists three concrete actions in a clearly named domain, matching the anchor for several specific actions with minor gaps. Not 5 because it omits the failure modes the skill actually handles (runtime errors, zero trades, abnormal results).

Completeness

The "what" is clear (diagnose, locate root cause, fix), but there is no "Use when..." clause or equivalent explicit trigger guidance — "failed or underperforming backtests" is the object of the action, only weakly implying when to invoke the skill. Per the judging guideline, a missing explicit trigger caps completeness at 3.

Trigger Term Quality

"failed", "underperforming", "backtests", and "root cause" are phrases users would naturally say when needing this skill. A few natural variants are missing ("error", "poor results", "losing strategy"), so it does not reach the comprehensive synonym coverage of 5.

Distinctiveness Conflict Risk

"backtests" carves out a distinct niche with minimal conflict risk against generic skills. Minor overlap risk remains with closely related strategy/quant skills, and "fix the issue" is generic, so it falls short of the clear-niche-with-distinct-triggers anchor at 5.