WebMCP Runs In Chrome. My 400 Daily Tool Calls Don't.
Google I/O 2026 shipped WebMCP and half the AI Twitter timeline is calling it "the new MCP standard." It isn't. It's a browser-scoped protocol that solves a completely different problem than the MCP servers currently running on your VPS at 3 AM. Here's the boundary Google buried in the docs, and how to decide which side of it your agent belongs on.
What WebMCP actually is (and isn't)
WebMCP is a browser-scoped tool protocol. It exposes tools to an agent from inside a Chrome tab — the tools live in the page, auth is the user's active session, and the runtime is the browser itself. That's the entire surface area.
When Google says "agentic web," they mean an agent that operates inside a tab the user already has open, using the cookies and OAuth tokens already loaded. That's a legitimate and useful pattern:
