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by yjcho9317 75 days ago
I built and shipped an MCP server (NAVER WORKS integration) so I've been on both sides of this.

My server talks to a corporate messaging API — one bad tool call could blast messages to an entire org. I ended up writing input validation for every single tool by hand because there's no standard for it. Even then, Claude Code will happily call tools in a loop with hallucinated parameters. Saw it happen more than once.

Rate limiting would've probably stopped most of that, but MCP doesn't really give you a clean place to enforce it.

I also got the server listed on mcp.so and mcpservers.org with basically zero review. It's closer to a directory than anything else.

I do mobile app security for a living (banking apps), and yeah — same story there. You can't rely on the thing executing the action to control itself.

1 comments

Hit this exact thing with Linear's GraphQL client - agents invent field names that moved in the last schema update. Typed wrapper here if it helps: https://beepack.ai/package.html?slug=linear-api