Agent interoperability concept
What are Agent Skills?
ReferenceWhat are Agent Skills? They are reusable instructions and supporting files that help an AI agent handle a kind of task. A skill usually lives in a folder with a SKILL.md file: its metadata helps the agent recognize when it may apply, and its instructions describe what to do. Some skills also include reference files, templates, or scripts.
Reviewed 2026-10-09
A reusable playbook for a task
An Agent Skill packages instructions for a recurring task, such as following a team’s writing rules or using a particular review process. The format’s required file is named SKILL.md, and a skill is organized as a folder that can also contain supporting materials. This is why people sometimes use “skill” to mean the folder and “SKILL.md” to mean its central instruction file.
The SKILL.md file has YAML front matter—a small metadata section at the top—and Markdown content for the instructions. The specification requires a name and a description; the description should say what the skill does and when to use it. Other files, such as references, templates, or scripts, are optional.
The agent loads details when they are relevant
A compatible agent first discovers a skill and uses its name and description to judge whether it may fit the task. When the skill is activated, the agent reads its SKILL.md instructions. It can then load referenced material or use bundled scripts if needed. This staged loading is often called progressive disclosure: the agent does not need to put every skill’s full instructions into context at the start.
A skill guides the agent’s approach; it does not, by itself, grant access to a tool or data source. What it can do depends on the agent and its available permissions and tools. Skills may contain scripts, and instructions can influence planning and tool use, so review a skill before trusting it.
Instructions and connections solve different needs
Skills sit alongside agent tools, prompts, and protocols. A one-time prompt gives instructions for a particular request; a skill packages a procedure that may be reused when relevant. Tools let an agent take actions or retrieve information, subject to the host’s setup and permissions.
As checked on 2026-10-09, the Model Context Protocol (MCP) specification dated 2026-07-28 describes MCP as a way for applications to connect language models with external data and tools. In plain terms, a skill can explain how to use a connected tool—for example, what checks to perform before searching a database—while MCP can provide the connection. They can be used together. Read more about agent interoperability.
A skill is not a magic capability
A SKILL.md file is not a special model, a separate agent, or a guarantee that a task will be done correctly. It is a structured way to give an agent instructions and, optionally, supporting materials. The agent still needs a compatible host to discover and load the skill, and may need tools or permissions to carry out its steps.
The format is designed for reuse across compatible agent products, but a shared file format does not mean every product behaves identically or supports every optional feature. For example, the Agent Skills specification labels the allowed-tools field experimental and says support can vary. If a skill includes scripts or instructions that affect tools, check what it contains and what access the agent has.
Questions people ask
What does SKILL.md contain?
It contains required metadata in YAML front matter, including a name and description, followed by Markdown instructions. A skill folder can also include optional files such as references, templates, or scripts.
Does an Agent Skill give an agent access to tools?
Not by itself. A skill can explain how to use a tool, but the agent needs that tool to be available through its host and permissions. MCP, for example, is a protocol for connecting applications to external data and tools.
Can the same skill work in different agent products?
The format is intended to be reusable across compatible agents, and multiple products support it. Check the product’s documentation: support for optional fields and behavior can vary.
Learn more
- Agent Skills Specification
Check the required SKILL.md structure, metadata, and optional files.
- Skills
See how one product discovers and uses skills, and what to consider when reviewing them.
- Model Context Protocol Specification
Read the dated specification for the external connections MCP provides.
What changed
Sources
Part of Agent interoperability: Check discovery and compatibilityMatch the interface to the user