[skills](https://carteblanche.com/index.md) / [code](https://carteblanche.com/index.md?category=code)

# skill-development

what it does

This skill should be used when the user wants to "create a skill", "add a skill to plugin", "write a new skill", "improve skill description", "organize skill content", or needs guidance on skill structure, progressive disclosure, or skill development best practices for Claude Code plugins.

also needs

Mentions things that aren’t included:

- `scripts/init_skill.py` (a script)
- `scripts/package_skill.py` (a script)

by anthropics · version 1 · license Apache-2.0

We imported this skill from its author’s repository. Is this yours? [Claim this listing](https://carteblanche.com/claim/skill-development)

Verified · Before and after: 2 models · 1 try per case · [View source](https://github.com/anthropics/claude-plugins-official/tree/0412be76f50ab4f4f8abff3753efa9269fbbca5b/plugins/plugin-dev/skills/skill-development) · [Install from your agent](https://carteblanche.com/connect.md) · [Download .zip](https://carteblanche.com/skills/skill-development/download)

## Compare the answers

Answers from Claude Sonnet 5.5 and GPT-6.1 Sol · try 1 of 1

Same request, same model, once with the skill and once without. Read both and judge for yourself.

[Compare the answers](https://carteblanche.com/skills/skill-development/compare)

## The models

2 models

Claude Sonnet 5.5

made by Anthropic

claude-sonnet-5-5 · revision not reported by the provider

1 try per case · tested 7 Nov 2026

GPT-6.1 Sol

made by OpenAI

gpt-6.1-sol · revision not reported by the provider

1 try per case · tested 7 Nov 2026

## The tasks

written by Carte Blanche

**example-1**

“I'm building a Claude Code plugin for managing database migrations and want to add a skill for it. It should cover writing migration files, rolling back, and handling schema conflicts. Can you help me create the skill, including how to structure the folder and what should go in SKILL.md versus separate reference files?”

**example-2**

“My plugin has a skill called 'api-testing' but it almost never triggers. The description just says "Helps with API tests." Can you rewrite it so it fires on phrases like "write integration tests for this endpoint" or "mock an API response"? Also, my SKILL.md is about 600 lines long, so please suggest how to split it up using progressive disclosure.”

## Install

Download the .zip and unzip it. Put its files, in a folder named `skill-development`, here:

Claude Code · `~/.claude/skills/` · Every project. For one project only, use .claude/skills/ inside it.

Codex · `~/.agents/skills/` · Every project. For one repository only, use .agents/skills/ inside it.

Cursor · `~/.cursor/skills/` · Cursor also reads the Claude Code and Codex folders above.

Then start a new session and ask for what the skill does. Other agents that read SKILL.md have their own skills folder; check their docs.

Or [install from your agent](https://carteblanche.com/connect.md): ask it to install `skill-development` from Carte Blanche.

## Badge for your README

Carte Blanche: Verified

Paste this into the skill’s README. It links to this page, and shows how the listing stands whenever it’s loaded.

```
[![Carte Blanche](https://carteblanche.com/badge/skill-development.svg)](https://carteblanche.com/skills/skill-development)
```

## About this test

- **tested**: 7 Nov 2026
- **version tested**: v1
- **cases**: 2
- **tries per case**: 1 try per case
- **run without the skill**: yes
- **cases written by**: Carte Blanche
- **size**: 33730 characters

What this shows, and what it doesn’t

How 2 models answered these 2 requests, with and without the skill. It says nothing about other models, and it doesn’t limit what your own agent can do.

[How we test](https://carteblanche.com/how-it-works.md)