What is a skill.md file?
A skill.md file is a Markdown file with YAML frontmatter that packages domain expertise for AI coding agents. Drop one into your project and Claude Code, Cursor, or Codex activates it automatically when the task description matches. The format is the open agentskills.io standard, supported by 27+ agents, and every skill.md file on mdskills.ai is free to download.
Que problema ele resolve?
Sem skills, você repete os mesmos prompts complexos toda vez que quer que um agente faça algo específico — gerar um PDF, construir um design system, escrever testes com Playwright. SKILL.md empacota essas instruções uma única vez para que qualquer agente compatível possa utilizá-las automaticamente. Skills são carregadas sob demanda, então não sobrecarregam a janela de contexto do seu agente.
Como funciona
Uma skill é uma pasta contendo um arquivo SKILL.md com frontmatter YAML e instruções em markdown. No mínimo, uma skill precisa de um nome e uma descrição.
Campos do frontmatter
| Campo | Obrigatório | Descrição |
|---|---|---|
| name | Sim | Identificador único. Máximo de 64 caracteres, letras minúsculas, números e hífens. |
| description | Sim | O que a skill faz e quando ativá-la. Máximo de 1024 caracteres. |
| license | Não | Identificador de licença SPDX ou referência a um arquivo de licença. |
| compatibility | Não | Lista de agentes compatíveis e requisitos de ambiente. |
| metadata | Não | Pares chave-valor arbitrários (autor, versão, tags). |
| allowed-tools | Não | Lista delimitada por espaços de ferramentas pré-aprovadas para o agente. |
How to install a skill.md file
Three ways to install a skill.md file from mdskills.ai. Every path is one action on a skill's detail page or one line in your terminal.
- Install from the terminal. One command, resolves the latest version, drops the SKILL.md file into the right folder for your agent.
npx mdskills install <slug> - Download from mdskills. Click Download on any skill's detail page to get the
SKILL.mdfile directly. Save it into your project's.claude/skills/<name>/(or the equivalent path for Cursor, Codex, or your agent). - Copy the raw SKILL.md text. On any skill's detail page, click Copy SKILL.md to grab the file contents to your clipboard. Paste into your agent, a new file in your project, or a chat window.
How to download a skill.md file
Every skill on mdskills.ai has a green Download button on its detail page. Downloads are free. You get either the raw SKILL.mdfile (for standalone skills) or a .ziparchive of the skill folder (when the skill includes scripts, references, or assets alongside the SKILL.md).
Examples of skill.md files
Five well-written skill.md files worth reading before you author your own. Each one shows a different pattern: format converters, opinionated design systems, ambient content, meta-workflows, and multi-agent pipelines.
- markitdown: convert PDFs, Word, Excel, PowerPoint, images, and audio to clean Markdown. The canonical example of a narrow-scope skill with a crisp description.
- ui-ux-pro-max: an encoded-preference skill. A full design opinion (spacing, type, color, motion) that guides Claude away from generic AI-looking UI.
- scroll-experience: builds long-form editorial pages with pacing, section rhythm, and typographic hierarchy. Great example of a skill that reshapes output structure.
- claude-code-game-studios: a meta-skill that captures a full workflow for spinning up game studios inside Claude Code. Shows how skills can encode multi-step processes, not just single-shot tasks.
- pixel-agents: orchestrates multiple pixel-art agents for game assets. A good reference for skills that coordinate several sub-tasks under one description.
Browse the full library on the Skills page.
skill.md vs AGENTS.md vs cursorrules
| Format | Load model | Best for |
|---|---|---|
| SKILL.md | On-demand, description-based activation | Deep, domain-specific knowledge you don't want in every session |
| AGENTS.md | Every session, always loaded | Baseline project conventions and cross-agent instructions |
| CLAUDE.md | Every session, Claude Code only | Claude Code-specific instructions and project state |
| .cursorrules | Every session, Cursor only | Cursor-specific rules and behavior overrides |
Divulgação progressiva
Skills usam um modelo de carregamento em três fases para manter as janelas de contexto eficientes:
- Descoberta — O agente lê apenas o nome e a descrição (~100 tokens)
- Ativação — Quando uma tarefa corresponde, o SKILL.md completo é carregado (<5000 tokens)
- Execução — O agente segue as instruções, carregando arquivos referenciados conforme necessário
Quem oferece suporte
O formato SKILL.md é compatível com Claude Code, Cursor, OpenAI Codex, Gemini CLI, VS Code, GitHub Copilot, Amp, Roo Code, Goose, Windsurf, Continue e muitos outros. A lista completa de agentes compatíveis é mantida em agentskills.io.
Frequently asked questions
What is a skill.md file?
A skill.md file (also written SKILL.md) is a Markdown file with YAML frontmatter that packages domain expertise for AI coding agents like Claude Code, Cursor, and Codex. Drop one into your project and the agent uses it as reusable knowledge, activated by name or context.
How do I download a skill.md file?
Browse skills on mdskills.ai, open the skill's detail page, and click the green Download button to save the skill.md file (or the full skill folder as a .zip). You can also install directly from the terminal with npx mdskills install owner/skill-name.
How do I install a skill.md file in Claude Code?
Three ways, all from mdskills.ai. Run npx mdskills install <slug> in your terminal. Or open the skill on mdskills.ai and click Download to save the SKILL.md file into .claude/skills/<name>/. Or click Copy SKILL.md to copy the file contents to your clipboard and paste into your project. Claude Code discovers the file automatically once it is in .claude/skills/ (project-level) or ~/.claude/skills/ (user-level).
What is the difference between skill.md and AGENTS.md?
A skill.md is loaded on demand when the agent decides its description matches the task at hand. AGENTS.md is loaded every session as always-on project instructions. Skills are progressive-disclosure knowledge; AGENTS.md is baseline convention.
What is the difference between skill.md and cursorrules?
cursorrules is Cursor's always-on instructions file at .cursorrules or .cursor/rules/*.mdc. A skill.md is a cross-tool, on-demand knowledge packet. Claude Code, Cursor, Codex and other agents all support it via the open agentskills.io spec.
Are skill.md files free?
Yes. Every skill on mdskills.ai is free to download and install. Some creators offer paid premium skills as well; free skills are marked and always available with one click.
Which AI agents support skill.md files?
The skill.md format is supported by 27+ AI coding agents, including Claude Code, Cursor, OpenAI Codex, Gemini CLI, VS Code, GitHub Copilot, Amp, Roo Code, Goose, Windsurf, Continue, Cline, and Aider. Anthropic created the format and maintains the open spec at agentskills.io; support is expanding across the field.
How do I write my own skill.md?
Create a folder named after your skill, add a SKILL.md file with YAML frontmatter (at minimum: name and description), and write instructions in Markdown below the frontmatter. Keep the description under 1024 characters and make it match-worthy: the agent decides when to load your skill by matching the task to the description text. Reference scripts, examples, or assets from the same folder.
Especificações relacionadas
Especificação Oficial
A especificação completa do SKILL.md é mantida em agentskills.io.
Ler a especificação completa