What is MCP?
MCP (Model Context Protocol), told as a story about one standard for toolboxes that any parrot can open.
Every parrot has a different toolbox shape. The same tool gets built five times.To give one rate tool to five parrots, it has to be built five times, once per box shape. Every workshop differs too.
Descriptions, request notes and results all differ.One workshop answers with a bean, another with a sheet, another with a table. Fitting every box anew soon takes more work than the tools themselves.
MCP is one standard for toolboxes. Any parrot opens a standard box right away.A box built to the standard (a server) holds tools, data and note templates. The parrot (a client) asks what is inside and writes its request note in the standard shape. Each box has its own key (permissions).
The parrot asks for the list, and the box always answers in one shape. Each box has its own key.The box may sit in the same room (stdio) or far away (HTTP); either way, the asking and answering look the same. A tool without a key stays shut even if it is on the list.
The standard only makes connecting easy. It says nothing about whether a box is safe.A stranger's box can hold a hidden note. Check who built it before opening, and give keys only to the tools you really need. Tools built by a thief: see security's supply chain and AI security. A parrot that opens boxes many times: the parrot that plans its own errands.
MCP = one standard for toolboxes. A box built to it (a server) holds tools, data and note templates, and any parrot (client) can ask for the list and open it right away. The standard only makes connecting easy; whether a stranger's box is safe is a separate question.
An open protocol between a model-side app (client) and tool/data providers (servers) for listing, calling and returning tools. Servers expose tools, resources and prompts; transport is stdio (same machine) or HTTP (remote). It standardizes the connection, not the server's trustworthiness — check permissions and provenance separately.
When grown-ups say it
- MCP (Model Context Protocol)
- The toolbox standard. Build one box and any parrot can open it.
- MCP server / client
- The standard box / the parrot opening it. The server offers tools; the client (the parrot-side app) asks and uses them.
- Tools · resources · prompts
- The three kinds of things inside. Tools you can run, data you can read, and ready-made note templates.
- Transport (stdio / HTTP)
- Same room or far away. stdio is the same machine, HTTP is across the network. The asking and answering look the same.
- Permissions
- One key per box. Only allowed tools open. Hand out only the keys you must.
- Tool calling
- The request note. Tools in a standard box are still asked for by note. → the toolbox
- Agent
- A parrot that opens boxes many times. The standard makes swapping boxes easy. → the parrot that plans its own errands
- Supply-chain risk
- A hidden note in a stranger's box. Check who built the box. → security's supply chain