skill-creator or mcp-builder: which one are you actually building?
They build different things. skill-creator helps you write a folder of instructions the agent reads. mcp-builder helps you write a server that exposes new tools. If the agent already has the access and only lacks the procedure, you want skill-creator.
The skill-creator skill helps you create, structure and refine your own skills, including the description text that determines when a skill is triggered at all. Install it before writing your first skill, because a well written skill with a vague description will simply never be used.
Best for
Teams turning repeated workflows into reusable skills, and anyone maintaining more than two skills.
Skip if
You have not yet repeated a workflow enough times to know what it really is.
Which one to install
Choose skill-creator when the thing you keep repeating is knowledge: a convention, a checklist, a procedure the agent should follow with the tools it already has. Nothing has to run, and the result is text you can review in a pull request.
The mcp-builder skill helps you design and implement Model Context Protocol servers, which is how an agent gets real capabilities such as querying your database or calling your internal API. Choose a server when the agent needs to act on a system, and a skill when it needs to follow a procedure.
Best for
Exposing internal systems, APIs and data sources to agents in a controlled way.
Skip if
What you need is procedural guidance, which is a skill and far cheaper to maintain.
Which one to install
Choose mcp-builder when the agent cannot reach the system at all. A server is the right answer to missing access, and the wrong answer to missing instructions, which is the mistake that produces servers with conventions buried inside them.
These two do not compete, and a mature setup usually has both: a server for the access and a skill for the house rules about using it. Installed together they trigger on different requests, so there is no overlap to resolve.