mutation-testing

Use when evaluating test quality on modules containing business logic, calculation utilities, or state machines to determine whether the tests provide genuine defect detection.

Quality

68%

Does it follow best practices?

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Securityby

Passed

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tessl review fix ./skills/mutation-testing/SKILL.md

Quality

Content

65%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.

The SKILL.md body is a well-structured, lean overview that uses progressive disclosure effectively by offloading executable detail to references/rule.md. Its weaknesses are the absence of any executable code/commands and missing validation checkpoints within the body itself.

Suggestions

Add a minimal copy-pasteable Stryker command (e.g., `pnpm stryker run --config stryker.config.ci.mjs`) to the body so actionability does not depend solely on the reference.

Include an explicit validation checkpoint in the Fix workflow (e.g., 're-run Stryker and confirm the mutation score meets the threshold before finishing').

Tighten the opening paragraph to remove the general coverage-vs-mutation explanation that Claude already knows.

Dimension	Reasoning	Score
Conciseness	The body is largely lean with terse Check/Fix/Explain/Code Review sections and a tight Quick Reference, though the opening paragraph restates the coverage-vs-mutation concept Claude largely already knows and could be trimmed.	4 / 5
Actionability	The body gives some concrete guidance (named tool Stryker, 80%+ threshold, focused one-module scope, kill surviving mutants) but defers all executable code and commands to references/rule.md, leaving the body itself incomplete as actionable instruction.	3 / 5
Workflow Clarity	The Fix section implies a rough sequence (set up Stryker, run a mutation report, improve tests), but the body has no validation checkpoints; because mutation testing is a batch operation, workflow clarity is capped at 3 even though the reference file carries the verification loop.	3 / 5
Progressive Disclosure	The body is a clear overview organized into well-labeled sections that points to a single one-level-deep reference (references/rule.md, which exists) with an explicit, well-signaled pointer, making navigation easy.	5 / 5
	Total	15 / 20 Passed

Description

71%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.

The description cleanly states both the capability and an explicit Use-when trigger with concrete module targets, making it highly complete and largely distinct. Its main weakness is narrow action breadth and missing common trigger synonyms like "mutation testing" or "coverage".

Suggestions

Add the term "mutation testing" to the description so users who say that phrase trigger the skill.

Mention 1-2 more concrete actions (e.g., 'set up Stryker and improve tests to kill surviving mutants') to raise specificity.

Include common synonyms such as "test coverage" or "test suite quality" to broaden natural trigger coverage.

Dimension	Reasoning	Score
Specificity	Names the domain and one concrete action ("evaluating test quality" to "determine whether the tests provide genuine defect detection") with concrete scope targets (business logic, calculation utilities, state machines), but does not list multiple distinct actions, so it is not comprehensive.	3 / 5
Completeness	It explicitly answers both what ("determine whether the tests provide genuine defect detection") and when ("Use when evaluating test quality on modules containing business logic, calculation utilities, or state machines") with concrete trigger phrases.	5 / 5
Trigger Term Quality	Relevant keywords like "test quality", "tests", and "defect detection" appear, but common variations users would say such as "mutation testing", "test coverage", or "unit tests" are missing.	3 / 5
Distinctiveness Conflict Risk	The focus on test-quality evaluation for business-logic modules is a clear niche with minimal conflict risk, though there is minor overlap with general testing or coverage skills.	4 / 5
	Total	15 / 20 Passed

Validation

93%

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 — 15 / 16 Passed

Validation for skill structure

Criteria	Description	Result
metadata_version	'metadata.version' is missing	Warning

	Total	15 / 16 Passed

Repository: thedaviddias/Front-End-Checklist
Path: skills/mutation-testing/SKILL.md
Commit: 30756a7

Reviewed: 5 days ago

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