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 skills add peintune/runjam --skill test-driven-developmentgit clone --depth 1 https://github.com/peintune/runjamWrote 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/peintune/runjam/test-driven-development)<a href="https://agentmods.dev/skills/peintune/runjam/test-driven-development"><img src="https://agentmods.dev/badge/skills/peintune/runjam/test-driven-development/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/peintune/runjam/test-driven-development"><img src="https://agentmods.dev/badge/skills/peintune/runjam/test-driven-development.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 5.1 | $0.00029 | $0.00212 |
| Opus 5.5 | $0.00012 | $0.00085 |
| Sonnet 5.5 | $0.00006 | $0.00042 |
| Haiku 4.5 | $0.00003 | $0.00021 |
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 1mo 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 (TDD)
Rule
Write the test first. Watch it fail. Write minimal code to pass.
Core principle: If you didn't watch the test fail, you don't know if it tests the right thing.
When to Use
Always for:
- New features
- Bug fixes
- Refactoring with behavior changes
Skip only for:
- Config file changes
- Documentation updates
- Non-functional changes (formatting, comments)
Process
- Red: Write a failing test
- Green: Write minimal code to pass
- Refactor: Clean up while keeping tests green
Anti-Patterns
- Writing implementation before the test
- Skipping the "watch it fail" step
- Writing tests that are too coupled to implementation
- Testing framework behavior instead of your code
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.
- 1mo ago First seen · 37 lines · 29 tokens per session scan A 1ec59ae17363
test-driven-development is a skill published in the GitHub repository peintune/runjam (228 stars, last pushed 3d ago), licensed MIT. It adds 29 tokens to every session and 212 once invoked, about $0.0001 per session on Opus 5.5. 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 2026-08-30.
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