name: claude-md-writer
description: Escribe y mejora CLAUDE.md siguiendo best practices. Usa cuando el usuario diga "crear CLAUDE.md", "mejorar CLAUDE.md", "actualizar CLAUDE.md", "revisar CLAUDE.md", "escribir instrucciones del proyecto", "agregar reglas al proyecto", "actualizar documentación", "optimizar documentación para Claude", o configure un nuevo repo.
allowed-tools: Read, Glob, Grep, Write, Edit

CLAUDE.md Writer

A skill for creating and optimizing CLAUDE.md files following official Anthropic best practices (2026-01).

When to Use This Skill

• Creating a new CLAUDE.md for a project
• Reviewing/auditing an existing CLAUDE.md
• Optimizing documentation for better Claude Code performance
• User asks about CLAUDE.md best practices

Golden Rule

Para cada línea, preguntá: "¿Eliminar esto causaría que Claude cometa errores?"
Si no, eliminalo. CLAUDE.md inflados causan que Claude ignore instrucciones.

"Think of CLAUDE.md as the 'unwritten knowledge' in your codebase"

Quick Tools

• /init - Genera CLAUDE.md inicial basado en la estructura del proyecto
• # key - Agregar instrucciones dinámicamente durante la sesión

@import Syntax

CLAUDE.md puede importar otros archivos:

See @README.md for overview and @package.json for commands.
Git workflow: @docs/git-instructions.md

Reference Documentation

For detailed best practices, read: docs/claude-md-best-practices.md

What to Include vs Exclude

CLAUDE.md vs Skills

Usage Modes

El skill acepta argumentos para diferentes flujos:

Content Triage

Antes de agregar contenido a CLAUDE.md, evaluar:

Detectar candidatos a Skill

Si el usuario quiere agregar info que cumple estos criterios, sugerir skill:
- "Cuando trabajes con X..." (condicional)
- "Para tareas de tipo Y..." (específico)
- "Si estás haciendo Z..." (situacional)
- Workflows con muchos pasos
- Conocimiento de dominio especializado

Respuesta sugerida:

Esta información parece ser domain knowledge/workflow específico que no aplica
a todas las tareas. Te sugiero crear un skill separado usando /skill-creator
o document-skills:skill-creator. Así se carga on-demand sin inflar cada sesión.

Process

Step 1: Analyze the Project

Before writing, gather information:

# Check project type and structure
ls -la
cat package.json 2>/dev/null || cat pom.xml 2>/dev/null || cat Cargo.toml 2>/dev/null

# Find existing documentation
ls -la docs/ 2>/dev/null
ls -la README.md 2>/dev/null

Identify:
- Tech stack (language, framework, build tools)
- Project structure (monorepo, single app, library)
- Existing documentation to reference

Step 2: Apply the Three Dimensions

Every CLAUDE.md must address:

Triage Check

Para cada pieza de información, preguntar:
1. ¿Aplica a TODAS las tareas en este repo? → CLAUDE.md
2. ¿Solo aplica a ciertos tipos de tareas? → Skill
3. ¿Cambia frecuentemente? → Link externo

Step 3: Write Following Best Practices

Length: Keep under 200 lines (ideal ~100 lines)

Structure (in order):
1. Repository Overview (1 paragraph)
2. Why This Exists (purpose, users)
3. Quick Start & Commands (bash with descriptions)
4. Architecture Overview (key patterns)
5. Key Development Rules (with emphasis)
6. References (links to detailed docs)

Emphasis for Critical Rules:

- **CRITICAL**: [Never violate this]
- **IMPORTANT**: [Always do this]
- **YOU MUST**: [Mandatory action]

Progressive Disclosure:
- Use file references instead of code snippets
- Link to external docs for detailed topics
- Keep CLAUDE.md focused on universal instructions

Step 4: Verify with Checklist

Before finalizing, verify:

• [ ] Under 200 lines?
• [ ] Passes Golden Rule? (each line prevents mistakes)
• [ ] Has WHAT, WHY, HOW sections?
• [ ] Critical rules have emphasis (CRITICAL/IMPORTANT)?
• [ ] Code snippets replaced with file references?
• [ ] Bash commands have descriptions?
• [ ] References external docs for detailed topics?
• [ ] No styling rules that should be in linters?
• [ ] Domain-specific content moved to skills?

Template

# CLAUDE.md

This file provides guidance to Claude Code when working with this repository.

## Repository Overview

[One paragraph: what this project is, tech stack, main purpose]

## Why This Exists

[What problem it solves, who uses it, business context]

## Quick Start & Commands

\`\`\`bash
npm ci        # Install dependencies
npm start     # Start dev server
npm test      # Run tests
npm run build # Production build
\`\`\`

> **Note**: [Any important setup notes, env files, postinstall behavior]

## Architecture Overview

[Key patterns, folder structure, main concepts - keep brief]

## Key Development Rules

- **CRITICAL**: [Most important rule that must never be violated]
- **IMPORTANT**: [Second most important rule]
- [Other rules...]

## References

- `/docs/` - Detailed documentation
- `README.md` - Project readme

Anti-Patterns to Avoid