Compare
Agent skills vs rules vs MCP servers
An agent skill is a SKILL.md file an AI agent loads on demand when a task matches its description. Rules are always-on instructions; MCP servers provide tools and data. This page explains the differences, where to find skills, and how to install one.
At a glance
| Skill | Rule | MCP server | |
|---|---|---|---|
| What it is | A SKILL.md file of procedural instructions | A short standing instruction file | A server exposing tools and data over a protocol |
| When it loads | On demand, when the task matches its description | By glob or always, regardless of relevance | When the agent calls one of its tools |
| Where it lives | .cursor/skills/<name>/SKILL.md or .claude/skills/ | .cursor/rules/*.mdc | A local or remote process, configured per client |
| Can it run code | It can bundle scripts and templates alongside instructions | No, it is text only | Yes, that is its purpose |
| Best for | Repeatable workflows and judgment, like an SEO audit | Always-on conventions, like code style | Live access to a system, like a database or an API |
What is an agent skill?
An agent skill is a folder containing a SKILL.md file: a named set of instructions an AI agent loads only when a task matches its description. The file states what the skill is for, when to use it, and the steps to follow, so the same workflow runs consistently instead of being re-explained in every prompt.
The format is documented in Anthropic's skills repository and supported by Cursor, Claude Code, and other agents that read SKILL.md files.
How is a skill different from a Cursor rule?
A rule is always-on context, applied by file glob or on every request, so it costs context whether or not it is relevant. A skill is loaded on demand: the agent reads only the short description up front and pulls in the full instructions when the task matches. Rules suit standing conventions like code style; skills suit multi-step workflows.
How is a skill different from an MCP server?
An MCP server gives an agent new capabilities, such as querying a database or calling an API. A skill gives an agent procedural knowledge: how to do a task well and in what order. They are complementary, and a skill often describes how to use tools an MCP server provides.
Where can I find agent skills?
Skills come from four kinds of source: official example repositories such as anthropics/skills, community awesome-lists on GitHub, general directories and registries, and focused directories like this one, which indexes 945 marketing skills with their source, license, and an automated security scan.
This directory is marketing-specific: every entry links to its source repository, shows the detected license, and carries an automated security scan, so you can see where a skill came from before installing it. Start with the full skill index.
How do I install a SKILL.md in Cursor?
Place the skill folder at .cursor/skills/<skill-name>/SKILL.md in your project, or at ~/.cursor/skills/ to make it available in every project. Many skills also publish an npx skills add command that copies the files for you. Cursor discovers the skill automatically and loads it when a task matches.
For step-by-step instructions covering Profound, coding agents, and manual copying, see how to use marketing skills.
Do skills work in tools other than Cursor?
Yes. SKILL.md is a plain-markdown convention shared across agents, so the same skill folder works in Claude Code under .claude/skills/, and the instructions can be pasted into other assistants such as Profound. Nothing in the format is tied to a single vendor.