MCP
MCP is an interface standard for giving models access to tools and data. Its value is not capability — it is not having to rewrite that integration for every client.
The problem it exists to solve
Before a standard, every integration was bespoke. Connecting a model to your ticketing system meant writing that glue for one framework, then again differently for the next, then again for whatever the team adopted six months later. The capability was identical each time; only the shape of the wiring changed.
MCP fixes the shape. A server exposes tools, resources and prompts over a defined protocol, and any client that speaks it can use them. The integration is written once and outlives the client that prompted it.
What a server actually contains
Three kinds of thing. Tools are actions the model can invoke, each with a schema describing its arguments. Resources are data it can read, addressed by URI. Prompts are reusable templates the client can offer a user directly.
The engineering is mostly in the schemas. A tool description is not documentation — it is the only thing the model has to decide whether and how to call it. Vague descriptions produce wrong calls, and the fix is almost always clearer wording rather than a better model.
Where this usually goes wrong
Using MCP where a function call would do
For one integration used by one application, plain function calling is less machinery. MCP pays off when the same capability must serve several clients, or outlive the one you are building today.
Writing tool descriptions for humans
The description is the model’s entire basis for choosing a tool. "Searches records" produces wrong calls; "Search customer orders by email or order ID; returns up to 20 most recent" produces right ones.
Exposing a whole database as one tool
A single query tool taking arbitrary input moves all the safety into the prompt. Several narrow tools with tight schemas are easier for the model to use correctly and far easier to bound.
Questions people actually ask
Is MCP tied to one model provider?
The protocol is open and client-agnostic. That is the point: a server you write is usable by any client implementing the standard, rather than by one vendor’s framework.
Do I need MCP to build agents?
No. Agents predate it and work fine with direct function calling. MCP is about reuse and portability of integrations, not about whether an agent can act.
What makes a good first MCP server?
Something read-only with a small, sharp surface — a search over your own documentation, or a query interface to one table. It teaches schema design without a tool that can damage anything.
Build it, free
Project briefs with the assessment criteria published before you start, and written code review on what you submit. No payment to apply or to complete.