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What is MCP?

Model Context Protocol. The USB for AI. The reason Claude (and every other major AI) can use real tools.


USB
For AI Agents
100s
Servers Available
Open
Standard
2024
Anthropic Released
The USB analogy
Before USB: every device had its own connector. Different cables for printers, mice, cameras. Pain.

USB standardized the plug. Any compliant device works with any compliant computer.

Before MCP: every AI integration was custom. Claude-specific Slack code. ChatGPT-specific GitHub code.

MCP standardizes the connector. Write one Slack integration. Every MCP-compliant AI can use it.
How it works (5 steps)
1
You run a server
An MCP server exposes tools — read_file, send_message, query_db.
2 · AI connects
Claude Code, Cursor, others connect to the MCP server.
3 · AI sees tools
Gets list of available tools + descriptions.
4 · AI asks server
When AI needs a tool, asks server to run it.
5 · Server returns result, AI continues reasoning
The result becomes part of the conversation context. AI uses it to take the next step.
Why It Matters Right Now
By itself, an AI is just text. With MCP, it can read your files, query your database, send a Slack message, deploy to Railway. The model + MCP = the agent.
Don't Over-Equip
Each MCP server costs context-window tokens before any conversation. Keep 5-8 daily-use; install niche ones per-project. 50 servers = bloated context.
Daily-use MCPs (iOS builder)
Install in Claude Code
  1. GitHub
    Issues, PRs, repos from chat
  2. Filesystem (built-in)
    Read/write project files
  3. App Store Connect
    Build status, metadata
  4. Railway
    Deploy + tail logs
  5. Plausible / PostHog
    "How did traffic do this week?"
  1. /mcp install <name>
    Inside Claude Code
  2. /mcp list
    See what's loaded
  3. /mcp remove <name>
    Trim when over-equipped
  4. Browse modelcontextprotocol/servers
    Reference catalog