Tsdd

Q: What is a Claude Code skill and how does the Tsdd skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Tsdd is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Engineering category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

Category: Engineering · Sub-category: testing · Last updated: 2026-06-13

lang:python

Test-Spec Driven Development (TSDD): tests are the durable specification, TDD is the operating discipline, prose carries only Why, and `CLAUDE.md` stays a navigation map. Load before production code, tests, ADRs, architectural decisions, `CLAUDE.md` edits, or any durable prose artifact that would duplicate tests or code. Also load when the user asks to write tests or define test behavior before implementation, including "test 書いて", "test 書いて", "テスト書いて", "pytest", "テスト環境", "TSDD", "Test-Spec Driven Development", "TDD で実装", "ADR を書いて", "decision record", or "executable specification".

About this skill (catalog notes)

Tsdd includes pricing or quota commentary; at least one code block. At roughly 2,658 words the SKILL.md is on the longer end of the catalog distribution.

License: MIT
Original author: furedea
Indexed lastmod: 2026-06-13
Catalog position: Engineering · testing
Indexed related skills: 10

How Tsdd fits the catalog

Tsdd sits in the Engineering category under the testing sub-topic in the ClaudSkills catalog. There are 10 related skills indexed alongside it; comparing a few before installing usually reveals which fits your workflow best.

These notes are auto-generated from features detected in the SKILL.md file and from this catalog's structure — they aren't part of the source repository.

What this skill does

Tsdd is a community-contributed Claude Code skill in the testing sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/tsdd/ and loads when your prompt matches the skill's trigger.

Who uses this skill

The Tsdd Claude Code skill is built for software engineers, backend developers, full-stack teams, and technical leads building and maintaining production systems. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 119,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/tsdd
curl -L https://claudskills.com/skills/tsdd/SKILL.md \
  -o ~/.claude/skills/tsdd/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/tsdd/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/tsdd/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\tsdd\SKILL.md on Windows. See the full install guide for step-by-step instructions.

📱 Install from your phone or desktop Telegram

Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Frequently asked questions

How do I install the Tsdd Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/tsdd/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.

What does the Tsdd skill do?

Is this skill free to install?

Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.

When should I use the Tsdd skill?

Use Tsdd when your Claude Code task falls under the Engineering category — specifically in the testing area. Claude Code auto-discovers installed skills and invokes the right one based on the task description, so you can also ask Claude directly (e.g. "use Tsdd" or describe the task and let Claude pick). Browse related skills at /category/engineering/.

What is a Claude Code skill and how does the Tsdd skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Tsdd is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Engineering category. Learn more at /learn/what-is-a-claude-skill/.

Attribution & license

Source: https://github.com/furedea/agent-harness/blob/96c7170bfbf7c1972523f18848e6f13088cb5245/agents/skills/tsdd/SKILL.md
License: MIT
Author: furedea

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA

furedea. (2026). Tsdd [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/tsdd/

BibTeX

@misc{tsdd-2026,
  author    = {furedea},
  title     = {Tsdd [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/tsdd/}
}

Embed this skill

Promote, attribute, or link this skill from your own README, blog post, or documentation. All three snippets are free to use — no sign-up, no API key. More distribution surfaces →

Badge

[![ClaudSkills](https://claudskills.com/badge/tsdd.svg)](https://claudskills.com/skills/tsdd/?utm_source=badge&utm_medium=readme&utm_campaign=skill_badge)

More Engineering skills

Browse all Engineering skills in the ClaudSkills registry, or explore these other picks from the same category:

Browse all Engineering skills → Top 100 skills

Part of ClaudSkills — the open registry for Claude Skills & Claude Code Skills. · What's New · Install guide · About · llms.txt

Part of Acreator Store — Adam Lankamer's AI tools: PerfectStudio · Ucaption · UTagger · AutoXPoster · TestYourSkills · AutomationFlows · Au Naturel · Telegram @acreatorstore