3 Principles for Designing Agent Skills | Block Engineering Blog

Skills are an open standard supported by most major AI coding tools: Claude Code, Goose, Cursor, Amp, GitHub Copilot, Gemini CLI, VS Code, and many more.

At their simplest, a skill is a folder with a SKILL.md file with a set of instructions that an agent can discover and load on demand. Think of it like a playbook. When an agent encounters a task that matches a skill’s description, it loads those instructions and follows them. Skills can also include supporting files like scripts, templates, MCP servers, and configuration files.

The beauty is in the portability. Write a skill once, and it works for anyone across any agent that supports the format.

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