Forecall - Lint your MCP tool descriptions before AI agents call them
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AI agents choose and call MCP tools by reading their names, descriptions and input schemas. Vague text means the wrong tool, wrong arguments, or no call at all. Forecall scores each tool out of 100 on six items (purpose, when to use, arguments, return value, constraints, examples), finds tools that are easy to mix up, and explains every issue with a code and severity. Free on the web with no sign-up, or run npx forecall lint locally and in CI.

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Weekly update from the maker:
Evaluations are live: real models (Claude Opus 5.5 and Sonnet 5.5, GPT-6 Astra and 6.1 Sol) answer utterances written for each of your tools, and you see tool choice, argument validity and false calls per model. On the Pro and Team plans.
The Failure KB is live: an MCP server of known MCP tool failures and their workarounds, in the official MCP Registry. Connect your agent with npx forecall setup.
The linter is now open source (Apache-2.0): https://github.com/forecall/forecall-cli. Two CI gates a reader asked for shipped the same day: --min-tool-score and --fail-on.
No tools/list JSON at hand? See Notion's official server, scored: https://forecall.dev/en/lint/sample
New data: in Smithery's 46 most-used servers, 69% of 1,118 tools never say when to use them. https://dev.to/nomunomu0504/we-checked-46-popular-mcp-servers-on-smithery-7-in-10-tools-never-say-when-to-use-them-4gb9