tdd

tdd is a skill for Claude Code from datj9/simple-mcp. It costs 94 tokens per session (916 once invoked), scanned A, original, no licence file.

A test-first development workflow that uses short red-green-refactor cycles: write a failing test, make it pass, then improve the code.

In plain words
What is it for?
Use it when building or changing code with tests first, including requests such as “TDD this” or “red-green-refactor.”
Why use it?
It helps catch incorrect behavior early and keeps code changes tied to tests instead of implementation details.

Skill for Claude Code

Written for Claude Code: installed under .claude/.

Good fit Use it when building or changing code with tests first, including requests such as “TDD this” or “red-green-refactor.”

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/datj9/simple-mcp/tdd
Install

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.

Any agent
npx skills add datj9/simple-mcp --skill tdd
Clone the repo
git clone --depth 1 https://github.com/datj9/simple-mcp

Made for: Claude Code.

Wrote 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.

agentmods badge for tdd

README.md
[![agentmods](https://agentmods.dev/badge/skills/datj9/simple-mcp/tdd/github.svg)](https://agentmods.dev/skills/datj9/simple-mcp/tdd)
Your own site
<a href="https://agentmods.dev/skills/datj9/simple-mcp/tdd"><img src="https://agentmods.dev/badge/skills/datj9/simple-mcp/tdd/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.

agentmods 80×15 button for tdd

Your own site · 80×15
<a href="https://agentmods.dev/skills/datj9/simple-mcp/tdd"><img src="https://agentmods.dev/badge/skills/datj9/simple-mcp/tdd.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 94 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 916 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00094 $0.00916
Opus 5.5 $0.00038 $0.00366
Sonnet 5.5 $0.00019 $0.00183
Haiku 4.5 $0.00009 $0.00092

Measured 1mo ago against content hash 0a01ff74cebe, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

tdd 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.

.claude/skills/tdd/SKILL.md · 101 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

Changes

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.

  1. 1mo ago First seen · 101 lines · 94 tokens per session scan A 0a01ff74cebe

Subscribe to this mod's changes

tdd is a skill published in the GitHub repository datj9/simple-mcp (0 stars, last pushed 1mo ago), with no licence file. It adds 94 tokens to every session and 916 once invoked, about $0.0004 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 2026-08-31.