MCP Server Tool Design 2026: FastMCP Patterns That Work
Learn MCP server tool design that actually works in 2026: FastMCP patterns, tool granularity, and schema choices that keep agents fast and accurate.
Chapter 1: Why MCP Tool Design Is the Bottleneck in 2026 The Model Context Protocol won. That part is settled. Two years after Anthropic open-sourced it, MCP is the default way agents reach external systems — every major model vendor speaks it, every serious agent framework ships a client, and the registry ecosystem has moved from "a JSON file of community servers" to something closer to a package manager. If you are building an integration for an LLM in 2026 and you are not exposing it over MCP, you are writing a bespoke adapter that only works inside one vendor's...