mcp-builder

Build MCP servers using FastMCP for Python or the MCP SDK for Node/TypeScript. Design agent-centric tools with input validation (Pydantic or Zod), proper tool registration, error handling, and support for multiple transports (stdio, SSE, HTTP) to enable LLMs to reliably interact with external services.

Design tools for complete workflows rather than simple API wrappers. Use agent-centric patterns with actionable error messages, character-limit awareness, pagination support, and clear tool naming conventions. Validate inputs rigorously and iterate based on agent evaluation feedback to optimize context efficiency.

Yes. FastMCP handles Python implementations while the MCP SDK covers Node/TypeScript. Choose based on your preferred language and existing infrastructure. Both support the same MCP protocol with identical transport options, validation patterns, and tool registration approaches.

Use Pydantic for Python (FastMCP) or Zod for Node/TypeScript (MCP SDK) to validate tool inputs. Both enforce type safety and generate clear error messages that help agents understand and recover from invalid requests, improving workflow reliability.

Create evaluations to measure how agents interact with your tools. Run agents through representative workflows, collect feedback on tool usability, and iterate on tool design—including naming, descriptions, error handling, and output formatting—based on agent performance metrics.

MCP supports stdio, SSE (Server-Sent Events), and HTTP transports. Choose based on your deployment model: stdio for local integrations, SSE or HTTP for remote or cloud-based agent interactions requiring more flexible connectivity.