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tdd

Test-driven development with red-green-refactor loops built around vertical slices (tracer bullets), not horizontal layers. Use when asked to "use TDD", "write test-first", "red-green-refactor", "build this with tests", or whenever a feature has a clear observable contract and would benefit from tests that outlive refactors. Complements the bundled test and add-tests skills — use this for the discipline, use those for the mechanics.

72

Quality

87%

Does it follow best practices?

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SecuritybySnyk

Passed

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SKILL.md
Quality
Evals
Security

Quality

Content

85%

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

A well-crafted, actionable skill body with a clear validated workflow and clean organization. The main opportunity is removing the overlap between the objective and core_principle sections to tighten token use.

Suggestions

Consolidate the "never refactor while RED" and "vertical slices, not horizontal layers" points so they appear once (e.g. only in core_principle) rather than being restated across <objective> and <core_principle>.

Consider folding the one-line <objective> into the opening of <core_principle> to avoid the two-section redundancy on the same two rules.

DimensionReasoningScore

Conciseness

The body is lean and assumes Claude's competence with no textbook padding, but the <objective> and <core_principle> sections restate two of three main points ("never refactor while red" and vertical slices / no all-tests-up-front), so it could be tightened.

2 / 3

Actionability

Concrete, executable directives throughout — "hard-code return 42", "Extract on the third occurrence", and a literal test-name example ("rejects requests missing an auth header") — give copy-ready guidance without needing code blocks.

3 / 3

Workflow Clarity

Five clearly numbered steps with explicit validation checkpoints (RED check, GREEN check, "Run tests after each small change", full-suite regression run) and error-recovery guidance for refactoring that breaks a test.

3 / 3

Progressive Disclosure

A single self-contained, well-sectioned file (objective, context, core_principle, process, anti_patterns, success_criteria) with no nested references and no content that needs splitting out, matching the well-organized single-file pattern.

3 / 3

Total

11

/

12

Passed

Description

90%

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, well-targeted description that clearly states what the skill does, when to use it, and how it differs from adjacent skills. Its only weakness is that the "what" is one composite methodology rather than a list of several concrete actions.

DimensionReasoningScore

Specificity

Names the domain and core techniques ("red-green-refactor loops", "vertical slices (tracer bullets)") but describes one composite methodology rather than a list of multiple distinct concrete actions. It is specific, not vague, yet not a comprehensive enumeration of concrete operations.

2 / 3

Completeness

Explicitly answers both what (TDD with red-green-refactor over vertical slices) and when ("Use when asked to... or whenever a feature has a clear observable contract and would benefit from tests that outlive refactors").

3 / 3

Trigger Term Quality

Includes natural trigger phrases users would actually say — "use TDD", "write test-first", "red-green-refactor", "build this with tests" — giving good coverage of likely requests.

3 / 3

Distinctiveness Conflict Risk

Carves a clear niche and explicitly distinguishes from sibling skills ("Complements the bundled test and add-tests skills — use this for the discipline, use those for the mechanics"), making mis-triggering unlikely.

3 / 3

Total

11

/

12

Passed

Validation

100%

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

Validation16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository
gsd-build/gsd-2
Reviewed

Table of Contents

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