Cursor throws 'MALFORMED_FUNCTION_CALL' when using Gemini 3 Pro or Gemini 3 Flash

Hey, thanks for the detailed report. The Request IDs, error frequency, and stack trace really help.

This looks like an issue with how Cursor formats function calls for the Gemini 3 API. Google’s API rejects them as invalid. There’s a similar bug in the backlog (forum discussion), but that one is specific to the MCP context.

For now:

  • Try other models (GPT-5.2, Claude Opus/Sonnet) if you need to work urgently
  • If there’s a pattern for when it breaks (specific prompts, context size, task type), share it here. It’ll help us reproduce it

I’ll update the thread if there’s any news.