What to know: the basics said what comes out is the model, plus the context, plus the tools it has. Tools are the part you can add to. Every tool you give it is a new kind of job it can do, and most people never add any.
MCP is the usual way of plugging one in. It stands for Model Context Protocol, and all it means is: a service describes what it can do, and the AI gets a set of tools for it. Once it is plugged in, the AI uses it like anything else it has.
The one worth doing first: your browser. It opens the widest door for the least effort.
Two steps. Install the Claude in Chrome extension from the Chrome Web Store. Then type /chrome in Claude Code to connect it. That same command later tells you whether it is connected, reconnects it when it drops, and is where you say which sites it may touch. You can also start with claude --chrome. It needs a direct Anthropic plan, so this is not available if you reach Claude through someone else's platform.
The part that matters: it drives your real browser, already signed in as you. Anything you can see in a tab, it can work with.
That means it can read a page and act on it: check what a site actually says, fill in a form from a file you have, pull the figures off a page and save them, read the console when something is broken, work inside a document or an inbox you are logged into.
What it costs. Every tool you connect takes up a bit more of your context window, before you type a word. Type /mcp in Claude Code to see what you have connected.
What it shares. Everything it reads through a door goes to the provider and is kept. A browser signed in as you is the widest door you can open. Worth deciding before you point it at your mail, not after.
Author's practice: keep it to a few. The browser is one of the few worth having.
Reveal on the spot: say what tools you have right now beyond reading and writing files. If the person is in a code tool and has added none, say so, name the one that would help them most for the work you have seen them do, and offer to set it up now.
Unlocks: automation of many different browser based accessible things such as: social media (X, LinkedIn), and sites unavailable via APIs.