# Create Skill

Guide for creating effective skills.

- Repository: https://github.com/NeoLabHQ/context-engineering-kit (1797 stars)
- Category: Testing
- License: GPL-3.0
- Last updated: 2026-08-26
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add NeoLabHQ/context-engineering-kit --skill create-skill -g -a claude-code -y`
Codex: `npx skills add NeoLabHQ/context-engineering-kit --skill create-skill -g -a codex -y`
Cursor: `npx skills add NeoLabHQ/context-engineering-kit --skill create-skill -g -a cursor -y`
Gemini CLI: `npx skills add NeoLabHQ/context-engineering-kit --skill create-skill -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add NeoLabHQ/context-engineering-kit`

## Description

Guide for creating effective skills. This command should be used when users want to create a new skill (or update an existing skill) that extends Claude's capabilities with specialized knowledge, workflows, or tool integrations. Use when creating new skills, editing existing skills, or verifying skills work before deployment - applies TDD to process documentation by testing with subagents before writing, iterating until bulletproof against rationalization

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Create Skill Command

This command provides guidance for creating effective skills.

## Overview

**Writing skills IS Test-Driven Development applied to process documentation.**

**Personal skills live in agent-specific directories (`~/.claude/skills` for Claude Code, `~/.codex/skills` for Codex)**

You write test cases (pressure scenarios with subagents), watch them fail (baseline behavior), write the skill (documentation), watch tests pass (agents comply), and refactor (close loopholes).

**Core principle:** If you didn't watch an agent fail without the skill, you don't know if the skill teaches the right thing.

**REQUIRED BACKGROUND:** You MUST understand Test-Driven Development before using this skill. That skill defines the fundamental RED-GREEN-REFACTOR cycle. This skill adapts TDD to documentation.

**Official guidance:** The Anthropic's official skill authoring best practices provided at the `/apply-anthropic-skill-best-practices` command, they enhance  `prompt-engineering` skill. Use skill and the document, as they not copy but add to each other. These document provides additional patterns and guidelines that complement the TDD-focused approach in this skill.

## About Skills

Skills are modular, self-contained packages that extend Claude's capabilities by providing
specialized knowledge, workflows, and tools. Think of them as "onboarding guides" for specific
domains or tasks, they transform Claude from a general-purpose agent into a specialized agent
equipped with procedural knowledge that no model can fully possess.

## What is a Skill?

A **skill** is a reference guide for proven techniques, patterns, or tools. Skills help future Claude instances find and apply effective approaches.

**Skills are:** Reusable techniques, patterns, tools, reference guides

**Skills are NOT:** Narratives about how you solved a problem once

### What Skills Provide

The rest: https://github.com/NeoLabHQ/context-engineering-kit/blob/HEAD/antigravity/skills/create-skill/SKILL.md