spec-driven-development

Creates specs before coding. Use when starting a new project, feature, or significant change and no specification exists yet. Use when requirements are unclear, ambiguous, or only exist as a vague idea.

1.90x

Quality

—

Does it follow best practices?

Impact

95%

1.90x

Average score across 3 eval scenarios

Securityby

Passed

No known issues

Evaluation results

97%

48%

Implementation Planning for New API Endpoints

Technical plan and task breakdown from approved spec

Criteria

Baseline

With context

Correct plan path

100%

Correct todo path

100%

Task has Description field

40%

70%

Task has Acceptance field

100%

Task has Verify field

70%

100%

Task has Files field

70%

100%

Files count ≤5 per task

100%

Dependency ordering

60%

100%

No implementation code

100%

tasks/ directory created

100%

90%

36%

Reliability Spec for the NewsSnap CLI

Spec from vague reliability requirement

Criteria

Baseline

With context

Assumptions block present

100%

Multiple explicit assumptions listed

100%

Vague requirement reframed

100%

Measurable success criteria

100%

No code written

100%

10%

Spec saved to file

100%

Open Questions section

100%

Objective section present

100%

Boundaries section present

100%

No unspecified features added

100%

87%

Commands section present

100%

51%

Specify a Dedupe Feature for a CSV Processing CLI

Spec document completeness for a new CLI feature

Criteria

Baseline

With context

Spec file saved

100%

Objective section present

100%

Commands section present

100%

Full executable commands

100%

Project Structure section present

100%

Code Style section present

100%

Code snippet in Code Style

100%

Testing Strategy section present

100%

Boundaries section present

100%

Three-tier Boundaries

100%

Success Criteria section present

100%

Assumptions surfaced

70%

100%

No implementation code

Repository: addyosmani/agent-skills
Commit: 70b7506

Evaluated: 3 days ago
Agent: Claude Code
Model: Claude Sonnet 4.6

Table of Contents

Specify a Dedupe Feature for a CSV Processing CLI Implementation Planning for New API Endpoints Reliability Spec for the NewsSnap CLI

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