Plain explanations of three words you keep meeting — skill, repo and MCP — for people who do not write code.
- A repo is a folder with a memory. It records every change to its files, so you can go back.
- A skill is written instructions. The model reads it when it recognises the task, so the work gets done your way.
- MCP hands a model tools. The model decides what to try, but the server decides what is possible, so its permissions matter more than your prompt.
- Add one thing at a time. A stack you do not understand is one you cannot tell is working.
Three words you keep meeting — skill, repo, MCP — explained without assuming you write code. Much of what is written about them assumes you are a developer.
A repo, in one sentence
A folder with a memory. It holds files, and it remembers every change anyone ever made to them — who, when, and what exactly changed.
That memory is the whole point. You can always go back. Most AI tooling is distributed this way, which is why "clone the repo" keeps appearing in instructions.
Fuller explanation: Repos, explained.
A skill, in one sentence
A written set of instructions a model loads when it recognises the task.
Not code — prose. A skill for writing legal contracts is a document explaining how your organisation writes contracts, which the model reads before starting. It turns "do this the way we do it" into something reusable.
Fuller explanation: AI skills, explained.
MCP, in one sentence
A standard way to hand a model a tool.
Instead of only producing text, a model connected to an MCP server can call actions: read this folder, query this database, post to this channel. The model still decides what to do; the server decides what is possible.
The permissions you grant an MCP server matter more than the prompt you write. A carefully worded instruction cannot stop an action the server allows, and a badly worded one cannot cause an action the server forbids.
Which is why guardrails is the page to read next.
When you connect a model to a tool, settle what that tool is allowed to do before you polish the prompt: wording steers the model, but the server’s permissions set the limits.
How they fit together
- A repo is where things live.
- A skill is how the model knows your way of doing something.
- An MCP server is what lets it act rather than only describe.
You can use any one without the others. Most useful setups combine all three — and the moment they do, the permission question stops being theoretical.
What to install, honestly
Start with nothing. Add one thing, use it for a week, then add the next.
The failure mode with all three is the same: installing a stack you do not understand, then being unable to tell whether it is working. A single tool you can reason about beats six you cannot.