Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/ahnafyy/skills-evals/test-driven-developmentnpx skills add ahnafyy/skills-evals --skill test-driven-developmentgit clone --depth 1 https://github.com/ahnafyy/skills-evalsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/ahnafyy/skills-evals/test-driven-development)<a href="https://agentmods.dev/skills/ahnafyy/skills-evals/test-driven-development"><img src="https://agentmods.dev/badge/skills/ahnafyy/skills-evals/test-driven-development.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00032 | $0.00108 |
| Opus 5 | $0.00016 | $0.00054 |
| Sonnet 5 | $0.00006 | $0.00022 |
| Haiku 4.5 | $0.00003 | $0.00011 |
Grade A, and why
test-driven-development scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
Test-Driven Development
Overview
Always demonstrate the bug or missing behavior with a failing test before touching implementation code.
When to Use
Use when fixing a reported bug, adding a feature, or refactoring untested code.
Verification
The failing test must be shown failing before the fix, and the full suite must pass after.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 4d ago First seen · 16 lines · 32 tokens per session scan A 5b9f2b4384d6
test-driven-development is a skill published in the GitHub repository ahnafyy/skills-evals (3 stars, last pushed 1mo ago), licensed MIT. It adds 32 tokens to every session and 108 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other skills, from other repositories
test-driven-development
Use when implementing any feature or bugfix, before writing implementation code.
old-coder
Evidence-first development — surround the implementation with an executable spec and a gauntlet of constraints (tests, types, coverage, mutation) so line-by-line review becomes optional. Use when the user explicitly asks for high-assurance or evidence-first work ("reliable", "TDD", "prove it works", "I won't read the…
skill-authoring
Guide creating Claude Code skills with TDD and persuasion principles. Use for new skill development.
tdd
测试驱动开发。当用户想以测试先行构建功能或修复 bug、提到 "red-green-refactor"，或想要集成测试时使用。.
superpowers-test-driven-development
Writing or fixing any code? Load first — write the failing test before the code.
evaluate-skill
Measure a skill's reliability — run it k times for a pass@k score, design or interpret its eval, or compare it against the base agent. Use when the user wants to run, design, or interpret a skill's eval, or write an .eval.yaml spec.