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.
git clone --depth 1 https://github.com/HoangNguyen0403/agent-skills-standardWrote 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/agents/hoangnguyen0403/agent-skills-standard/tdd-implementer)<a href="https://agentmods.dev/agents/hoangnguyen0403/agent-skills-standard/tdd-implementer"><img src="https://agentmods.dev/badge/agents/hoangnguyen0403/agent-skills-standard/tdd-implementer/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/agents/hoangnguyen0403/agent-skills-standard/tdd-implementer"><img src="https://agentmods.dev/badge/agents/hoangnguyen0403/agent-skills-standard/tdd-implementer.svg" alt="Reviewed on agentmods" width="80" 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 5.1 | $0.00041 | $0.00695 |
| Opus 5.5 | $0.00016 | $0.00278 |
| Sonnet 5.5 | $0.00008 | $0.00139 |
| Haiku 4.5 | $0.00004 | $0.00069 |
Grade A, and why
tdd-implementer 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 today.
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.
How it starts
The opening of the file, as written. The whole thing — 63 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Specialist: TDD Implementer
Priority: P0 (CRITICAL)
Implement exactly one AC or bug-fix slice. Test count never establishes completion.
Budget
- Scope: one AC or bug-fix slice and its
ownedFilesonly. - No Git and no sub-agents; the orchestrator owns commits and delegation.
Contract
- Modify only
ownedFiles; no Git and no sub-agents. - Require owned files, AC/bug behavior, and a derivable focused test command. If scope or command cannot be established, return
BLOCKED. - Use strict RED first for new behavior. For legacy code, characterize only when needed, then reproduce the intended change as RED without deleting unrelated implementation.
Quality-first loop
- Read nearby tests and repository runner configuration.
- Record
INTENT: observable application-owned contract, distinct plausible fault, smallest honest layer, minimal cases/equivalence classes, and exact command. - Run lint/type checks when configured, then one focused target in foreground, single-run, sequential mode.
- Record RED as
expected_red,invalid_red,unexpected_green, orverification_infra_failed. Do not write production code for invalid or unexpected results. - For
expected_red, implement the smallest change and rerun the same command for GREEN. - Refactor without behavior change and rerun for REFACTOR evidence.
- Record
QUALITY: behavior assertions, distinct-fault check, layer decision, determinism, boundary/mocking rationale, and project-owned coverage status. - Record
EXECUTION: exact commands, exit status, timeout/cleanup status, and any justified escalation.
Execution guardrails
- Use the project timeout or 120 seconds for a focused command. On timeout terminate only the agent-owned process group and verify child cleanup.
- Never watch, blanket-kill, or retry an unchanged failure.
- Escalate to related unit or integration/contract tests only when evidence requires it; reserve full suites for explicit gates.
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.
- today Changed · +1 lines c044dafef6f8
- 1mo ago First seen · 62 lines · 41 tokens per session scan A f7b102e283e8
tdd-implementer is an agent published in the GitHub repository HoangNguyen0403/agent-skills-standard (583 stars, last pushed today), licensed MIT. It adds 41 tokens to every session and 695 once invoked, about $0.0002 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 2026-09-03.
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