[Bug] 400 Bad request with Gemini while using Opencode - parameters.value schema missing type field

[ATLALALA]

Issue Description

When using Gemini in OpenCode, an INVALID_ARGUMENT error is triggered regardless of whether UnityMcp tools are used, preventing messages from being sent.

Full Error Message:

Bad Request: [{
  "error": {
    "code": 400,
    "message": "Unable to submit request because `unityMCP_manage_components` functionDeclaration `parameters.value` schema didn't specify the schema type field. Learn more: https://cloud.google.com/vertex-ai/generative-ai/docs/multimodal/function-calling",
    "errors": [
      {
        "message": "Unable to submit request because `unityMCP_manage_components` functionDeclaration `parameters.value` schema didn't specify the schema type field. Learn more: https://cloud.google.com/vertex-ai/generative-ai/docs/multimodal/function-calling",
        "domain": "global",
        "reason": "badRequest"
      }
    ],
    "status": "INVALID_ARGUMENT"
  }
}
]

Steps to Reproduce

Start the UnityMcp server and enable UnityMCP in OpenCode.
Use Gemini 3 pro preview in OpenCode.
Gemini returns a 400 INVALID_ARGUMENT error.

Additional Context

This issue only affects Gemini on my end; models like GPT and GLM are not affected. I have not tested whether ClaudeCode is affected.
There are no errors reported in the Unity Console or the server terminal.

Supplement

In the UnityMCP configuration, I used localHTTP and had a VPN enabled, which might also have caused an impact.