Build One AI Tool Server, Call It From Three Different Agents (MCP Explained)
One MCP server (~300 lines) built with FastMCP exposes four image-generation tools using Google's gemini-3.1-flash-lite-image model via a stateful Interaction API, callable from Claude Code, a Google ADK agent, and a Rust CLI without per-platform adapters. MCP standardizes tool definitions as JSON over stdio, enabling any AI agent to discover and invoke the same server, while the stateful API preserves conversation context across edits via interaction IDs.