Learn
Learn MCP
Plain answers about the Model Context Protocol, written for the person deciding whether their company needs an MCP server. Every figure links to its source.
Articles
Five questions, answered
- Explainer
Why MCP: the case for one protocol between agents and tools
Why does MCP exist, and why should a company care?
MCP is an open protocol that lets any AI client call any tool server. This page explains the problem it solves, who has adopted it, and what it changes for a company with an API.
- Comparison
MCP vs A2A: what each protocol is for
What is the difference between MCP and A2A?
MCP connects an agent to tools and data. A2A connects an agent to other agents. A side-by-side comparison with sources, and how to decide which one you need first.
- Explainer
The too-many-tools problem, and search-then-load
Why do agents get worse when you connect many MCP servers?
Every connected tool spends context before the conversation starts. This page shows the published numbers and the fix: search for tools first, load only the ones the task needs.
- Explainer
MCP Apps: interactive UI inside the conversation
What are MCP Apps?
MCP Apps is the official MCP extension that lets a tool return an interactive view instead of text. How it works, which clients render it, and how to ship one.
- Guide
How to build an MCP server for your company
How do I build an MCP server for my company without writing a server?
A practical plan: pick the jobs agents should do, turn them into a few well-described tools, put keys and logs in front, and publish. With or without a repo.
Definitions
The terms, in one sentence each
- MCP (Model Context Protocol)
- An open protocol that lets an AI application connect to external tools and data through one standard interface.Read more
- MCP server
- A program that lists tools, resources and prompts, and runs a tool when an AI client asks.Read more
- A2A (Agent2Agent)
- An open protocol for one AI agent to hand a task to another agent and follow its progress.Read more
- Search-then-load
- Giving an agent a search tool and loading a tool's full definition only when the task needs it, instead of loading every definition up front.Read more
- MCP Apps
- The official MCP extension that lets a tool return an interactive HTML view the client renders inside the conversation.Read more
- Hosted MCP server
- An MCP server someone else runs for you behind a URL, with keys and call logs, so there is no process or repo of your own to keep alive.Read more
More explainers: What is an MCP server?, What is WebMCP? and MCP for voice agents.
Questions
FAQ
About these pages and about PlugMCP.
- What is the fastest way to understand MCP?
- Read Why MCP first. It defines the protocol in one paragraph, names the problem it solves, and lists who has adopted it, with a source for each claim.
- Do I need to write code to have an MCP server?
- No. On PlugMCP you describe each tool in a form or on a workflow canvas, publish, and get a hosted URL with keys and call logs. The guide on building an MCP for your company walks through it.
- Where do the numbers on these pages come from?
- From the protocol specifications and from posts by the organizations that publish them. Each article ends with a numbered Sources list. A figure without a primary source is left out.
- Is PlugMCP the same thing as MCP?
- No. MCP is the open protocol. PlugMCP is a product: a directory of MCP servers, and a place to build, host and manage your own.
