CLAUDE.md Writer

A skill for creating and optimizing CLAUDE.md files following official Anthropic best practices.

Golden Rule

Para cada linea, pregunta: "Eliminar esto causaria 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 dinamicamente durante la sesion

@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 examples and validation checklist, see:

• references/good-example.md - Well-structured CLAUDE.md example
• references/bad-example.md - Common anti-patterns to avoid
• references/checklist.md - Quality validation checklist
• references/dead-weight-audit.md - Dead weight audit (5 criterios para recortar instrucciones)

What to Include vs Exclude

Include	Exclude
Bash commands Claude can't guess	Anything Claude can figure out by reading code
Code style rules that differ from defaults	Standard language conventions
Testing instructions and preferred test runners	Detailed API docs (link instead)
Repository etiquette (branch naming, PR)	Information that changes frequently
Architectural decisions specific to project	Long explanations or tutorials
Developer environment quirks (env vars)	File-by-file descriptions
Common gotchas or non-obvious behaviors	Self-evident practices

CLAUDE.md vs Skills

CLAUDE.md	Skills
Reglas amplias que aplican siempre	Conocimiento de dominio solo relevante a veces
Code style y workflow	Workflows especializados reutilizables
Convenciones del repo	Info que cambia por contexto
Se carga en cada sesion	Se cargan on-demand

Content Triage

Antes de agregar contenido a CLAUDE.md, evaluar:

Si el contenido es...	Entonces...
Regla que aplica a TODAS las tareas	Agregar a CLAUDE.md
Domain knowledge especifico	Sugerir crear skill
Workflow que solo aplica a veces	Sugerir crear skill
Info que cambia frecuentemente	No agregar, linkear a docs

Si el usuario quiere agregar info condicional ("Cuando trabajes con X...", "Para tareas de tipo Y..."), sugerir crear un skill separado.

Usage Modes

Invocacion	Comportamiento
/claude-md-writer	Proceso completo: analizar proyecto, escribir/mejorar CLAUDE.md
/claude-md-writer actualiza con la sesion	Extraer info relevante de la sesion actual y agregar a CLAUDE.md
/claude-md-writer agrega regla: [descripcion]	Agregar una regla especifica con el formato correcto
/claude-md-writer revisa y optimiza	Auditar CLAUDE.md existente, eliminar redundancias, mejorar enfasis
/claude-md-writer audita	Dead weight audit: aplicar los 5 criterios contra el setup actual (ver references/dead-weight-audit.md)
/claude-md-writer convierte a skill	Identificar contenido que deberia ser skill y extraerlo

Process

Step 1: Analyze the Project

Identify tech stack, project structure, and existing documentation.

Step 2: Apply the Three Dimensions

Dimension	Question to Answer
WHAT	What is this project? Tech stack? Structure?
WHY	Why does it exist? What problem does it solve?
HOW	How do I work on it? Commands? Workflows?

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]

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, run through the checklist in references/checklist.md.

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
\`\`\`

## 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]

## References

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

Dead Weight Audit

Cuando el usuario pida auditar su setup, aplicar los 5 criterios de references/dead-weight-audit.md contra cada regla:

1. ¿Default? — Claude ya lo hace sin que se lo digan
2. ¿Conflicto? — Contradice otra regla en el setup
3. ¿Redundancia? — Cubierto por otra regla o proceso
4. ¿Parche puntual? — Agregado para arreglar un output malo específico
5. ¿Vago? — Se interpreta distinto cada vez

Output esperado:

• Lista de cortes con razón en una línea cada uno
• Lista de conflictos encontrados entre archivos
• Versión limpia del CLAUDE.md sin dead weight

Proceso post-audit: eliminar → probar 3 tareas típicas → re-agregar solo lo que se rompió.

Anti-Patterns to Avoid

Anti-Pattern	Why It's Bad	Do This Instead
Code snippets	Become stale, waste tokens	Use file:line references
Styling rules	LLM is slow for deterministic tasks	Configure linters
Kitchen sink	Dilutes instruction effectiveness	Keep < 200 lines
No emphasis	Critical rules same weight as minor	Use CRITICAL/IMPORTANT
Auto-generated	Misses project nuances	Manually craft
Domain knowledge	Inflates every session	Move to skills