behavioral-mutation-analyzer

Analyzes surviving mutants from mutation testing to identify why tests failed to detect them. Takes repository code, test suite, and mutation testing results as input. Identifies root causes including insufficient coverage, equivalent mutants, weak assertions, and missed edge cases. Automatically generates actionable test improvements and new test cases. Use when analyzing mutation testing results, improving test suite effectiveness, investigating low mutation scores, generating tests to kill surviving mutants, or enhancing test quality based on mutation analysis.

Quality

76%

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tessl review fix ./skills/behavioral-mutation-analyzer/SKILL.md

Quality

Content

61%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

A thorough, well-referenced skill body with concrete examples and real tool commands, but it is verbose due to redundant example/operator/tool sections that overlap the bundled reference files, and its workflow omits the critical re-run-to-verify verification step for a batch analysis task.

Suggestions

Add an explicit final workflow step to re-run mutation testing and verify that the generated tests kill the previously surviving mutants, with a feedback loop (fix tests and re-run until the mutant is killed).

Remove the redundant "Practical Examples" section or fold it into Step 3, since those cases duplicate the root-cause examples already shown inline.

Replace the inlined "Mutation Operators Reference" and "Tool Integration" detail sections with brief pointers to references/mutation_operators.md and references/tool_integration.md, keeping only the essential run commands in SKILL.md.

Dimension	Reasoning	Score
Conciseness	The ~380-line body is mostly domain-relevant rather than generic fluff, but it carries noticeable redundancy: the "Practical Examples" section repeats cases already illustrated in Step 3, and the inlined "Mutation Operators Reference" and "Tool Integration" sections duplicate material that also lives in the referenced files.	3 / 5
Actionability	Provides concrete run commands (mvn org.pitest, npx stryker, mutmut), report file paths, and copy-paste-ready generated-test examples, but the actual report-parsing step ("Parse mutation results to identify all surviving mutants") is described abstractly without executable parsing code or scripts.	4 / 5
Workflow Clarity	The 6-step workflow is clearly sequenced with a Step 1 validation checklist, but it lacks an explicit verification feedback loop (re-run mutation testing to confirm generated tests actually kill the surviving mutants); for a batch operation processing many mutants, the missing feedback loop caps this dimension at 3.	3 / 5
Progressive Disclosure	All four referenced bundle files exist and are clearly signaled one level deep (inline callouts plus a closing References section), but inlining the mutation-operators and tool-integration material that is also in the reference files creates a minor organization gap.	4 / 5
	Total	14 / 20 Passed

Description

92%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A strong, third-person description that crisply states the skill's purpose, enumerates concrete root-cause categories, and provides an explicit multi-trigger "Use when" clause. Its only gap is the absence of specific mutation-testing tool names and synonyms as natural trigger terms.

Dimension	Reasoning	Score
Specificity	Lists multiple concrete actions—"Analyzes surviving mutants", "Identifies root causes including insufficient coverage, equivalent mutants, weak assertions, and missed edge cases", "Automatically generates actionable test improvements and new test cases"—with comprehensive, enumerated coverage rather than vague language.	5 / 5
Completeness	Explicitly answers both what ("Analyzes surviving mutants... Identifies root causes... generates actionable test improvements") and when ("Use when analyzing mutation testing results, improving test suite effectiveness, investigating low mutation scores...") with concrete trigger phrases.	5 / 5
Trigger Term Quality	The "Use when" clause covers natural phrases users would say ("analyzing mutation testing results", "investigating low mutation scores", "generating tests to kill surviving mutants", "enhancing test quality"), but omits common synonyms and specific tool names (PIT, Stryker, mutmut) that users would naturally mention.	4 / 5
Distinctiveness Conflict Risk	Mutation-testing analysis is a clear, narrow niche with distinct triggers ("surviving mutants", "mutation testing results", "low mutation scores") that are unlikely to fire for unrelated skills.	5 / 5
	Total	19 / 20 Passed

Validation

100%

Warnings & errors only

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository: ArabelaTso/Skills-4-SE
Path: skills/behavioral-mutation-analyzer/SKILL.md
Commit: 4f38503

Reviewed: 25 days ago

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