fastmcp-lint is a free Python tool designed for static analysis of FastMCP servers, focusing on schema quality issues. It performs pure Python AST analysis to help developers identify problems with tool descriptions generated from Python docstrings. By catching errors before deployment, the tool enhances documentation hygiene and improves the reliability of tool usage. Users can run simple commands to check their server files, with detailed output on errors and warnings, ensuring that each tool's functionality is well-documented.

The program also offers a suggest mode that provides templates for missing docstrings, making it easier for developers to fill in necessary documentation. Additionally, fastmcp-lint integrates smoothly into CI pipelines, allowing for automatic checks during development. With features like JSON output for detailed grading and compatibility with GitHub Actions, it serves as a comprehensive solution for maintaining high-quality documentation standards in FastMCP projects.