A planning aid for test-driven development (TDD), a way of writing tests before or alongside code. It turns domain rules and a user story into Gherkin scenarios and a unit-test list, adding a use case when flows or states are complex.

Use it to document business rules, write acceptance scenarios, identify unit tests, and model complex workflows or state changes.

It helps turn a feature idea into clear behaviour and a practical test plan before implementation starts.

tdd-plan — Skill for Claude Code by msbaek

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 msbaek/msbaek-claude-plugins --skill tdd-plan

Clone the repo

git clone --depth 1 https://github.com/msbaek/msbaek-claude-plugins

Made for: Claude Code.

Or install msbaek-tdd, the plugin that ships this one along with the rest of its 28 skills, 10 agents, 2 hooks.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/msbaek/msbaek-claude-plugins/tdd-plan.svg)](https://agentmods.dev/skills/msbaek/msbaek-claude-plugins/tdd-plan)

Your own site

<a href="https://agentmods.dev/skills/msbaek/msbaek-claude-plugins/tdd-plan"><img src="https://agentmods.dev/badge/skills/msbaek/msbaek-claude-plugins/tdd-plan.svg" alt="Measured on agentmods" height="20"></a>

Per session 72 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 3,091 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.

Model	Per session	Once invoked
Fable 5.1	$0.00072	$0.03091
Opus 5	$0.00036	$0.01545
Sonnet 5	$0.00014	$0.00618
Haiku 4.5	$0.00007	$0.00309

Measured today against content hash b89f1b27495d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

tdd-plan 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.

msbaek-tdd/skills/tdd-plan/SKILL.md · 168 lines

The source is not reproduced here

No licence file

Read it on GitHub

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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.

today Changed · -2 lines b89f1b27495d
4d ago Changed · -322 lines · +13 tokens per session 28e0292454e2
8d ago First seen · 492 lines · 59 tokens per session scan A a5b70e781a46

Subscribe to this mod's changes

tdd-plan is a skill published in the GitHub repository msbaek/msbaek-claude-plugins (8 stars, last pushed today), with no licence file. It adds 72 tokens to every session and 3,091 once invoked, about $0.0004 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.

Planning TDD Testing

engram-testing-coverage

TDD and coverage standards for Engram. Trigger: When implementing behavior changes in any package.

Gentleman-Programming/engram · 25 tokens

nw-fp-clojure

Clojure language-specific patterns, data-first modeling, REPL-driven development, and spec.

nWave-ai/nWave · 25 tokens

strict-tdd

Strict RED->GREEN->REFACTOR test-driven development with enforcement. Never write production code before a failing test. Atomic commits per TDD cycle.

a5c-ai/babysitter · 34 tokens

mobiai-mobile-tdd

You MUST use this before writing any implementation code for a mobile feature, bug fix, refactor, or behavior change. Tests come before implementation — no exceptions.

ArisGuimera/MobiAI-Core · 38 tokens

tdd

This skill should be used when the user wants to implement features or fix bugs using test-driven development. Enforces the RED-GREEN-REFACTOR cycle with vertical slicing, context isolation between test writing and implementation, human checkpoints, and auto-test feedback loops. Uses multi-agent orchestration with the…

glebis/claude-skills · 92 tokens

conductor-implement

Execute tasks from a track's implementation plan following TDD workflow.

rmyndharis/antigravity-skills · 17 tokens