MCP Explained: The Shared Plug That Connects AI Models to Tools

Business Pill 41 · The shared plug for AI tools

Every link between an AI model and a company system can be a custom build. The Model Context Protocol, MCP, replaces that with one shared plug.

A short explainer video. The numbers in it are round numbers for illustration.

The Short Answer

An engineer is teaching a robot to use the company systems. The calendar needs one custom connector. The customer database needs another. The invoices need a third.

Then two more robots arrive. With three robots and 10 systems, that is 30 connectors to build and to maintain.

One Shared Plug

So the industry agreed on one shared plug. It is called the Model Context Protocol, MCP for short: a standard way to connect an AI model to tools and data.

Now each system builds one plug, and each robot builds one socket. That is 13 pieces instead of 30.

A Worked Example

The arithmetic uses the video’s round numbers. Without a standard, every robot needs its own connector to every system: 3 robots times 10 systems is 30.

With the standard, each of the 10 systems builds one plug and each of the 3 robots builds one socket: 10 plus 3 is 13. This publication’s arithmetic from the video’s example: that is 17 fewer pieces.

In the video’s words, custom connectors multiply, while a shared plug adds up.

Bar chart: 30 custom connectors for 3 robots and 10 systems, against 13 pieces with one shared standard
Three robots times 10 systems is 30 connectors. One plug per system plus one socket per robot is 13. Round numbers for illustration.

Why It Matters

A tool built once works with every assistant that speaks the standard. That is the business point: the work of connecting is done once, on the standard, not again for each assistant.

So the question to ask is whether the tools we buy speak the shared standard.

The Question to Ask

  1. Do the tools we buy speak the shared standard?

See It in the News

Shopify Brings Agent Tools Into Checkout. A news piece on agent tools reaching a checkout flow through a standard connection.

How This Concept Connects

Layer 4 of 8 · Agents & Workflows, on the Business Engineer Concept Map

  • MCP builds on Tool Use. MCP is a standard way to connect a model to tools and data, so each system builds one connector instead of many.
  • Computer Use contrasts with MCP. Computer use reaches systems with no connector through the screen, slower than a real connector such as MCP.
  • MCP is an example of Extensibility Is Control. MCP is a shared plug, and the extensibility lesson says whoever defines how others connect shapes what is built on top.
  • MCP constrains Switching Costs. Switching costs include rebuilt integrations; the lesson advises open standards, and a connect-once standard like MCP is one.
Business Engineer framework
The Agentic Harness War
Connector standards shape the harness competition.
Business Engineer framework
The War of Agents’ Architectures
Protocols in the agent-architecture war.
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