Equipping agents for the real world with Agent Skills

As model capabilities improve, we can now build general-purpose agents that interact with full-fledged computing environments. Claude Code , for example, can accomplish complex tasks across domains using local code execution and filesystems. But as these agents become more powerful, we need more composable, scalable, and portable ways to equip them with domain-specific expertise. This led us to create Agent Skills : organized folders of instructions, scripts, and resources that agents can discover and load dynamically to perform better at specific tasks.

Skills extend Claude’s capabilities by packaging your expertise into composable resources for Claude, transforming general-purpose agents into specialized agents that fit your needs. Building a skill for an agent is like putting together an onboarding guide for a new hire. Instead of building fragmented, custom-designed agents for each use case, anyone can now specialize their agents with composable capabilities by capturing and sharing their procedural knowledge. In this article, we explain what Skills are, show how they work, and share best practices for building your own.

At its simplest, a skill is a directory that contains a SKILL.md file . This file must start with YAML frontmatter that contains some required metadata: name and description . At startup, the agent pre-loads the name and description of every installed skill into its system prompt.

This metadata is the fi rst level of progressive disclosure : it provides just enough information for Claude to know when each skill should be used without loading all of it into context. The actual body of this file is the second level of detail. If Claude thinks the skill is relevant to the current task, it will load the skill by reading its full SKILL.md into context.