Gemini 2.5 Pro: MCP & Function Calling

Gemini API
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1

Hey everyone,

I’m trying to combine function calling with MCP tools. Both work fine on their own, but when I do something like:

    response = await ai.models.generateContent({
      model: config.models.gemini,
      contents: messages,
      config: {
        systemInstruction: agentSystemPromptContent,
        tools: [
          // { googleSearch: {} },
          // { urlContext: {} },
          mcpToTool(client),
          { functionDeclarations: toolDefinitions },
        ],
        thinkingConfig: thinkingConfig,
      }
    })

I get this notice:

Automatic function calling with CallableTools and Tools is not yet supported.

Question: When will it be possible to use them together?
That would be super interesting.

Also, quick question for the MCP team: when will compatibility be fully supported? Right now it looks like only tool calls are available experimentally. If I’m not mistaken.

And, when will it be possible to use function calling with googleSearch: {}?

3

Hii, multi-tool support is still a work in progress, and we can’t share an exact timeline yet. However, with the Live API, you should be able to use multiple tools together. You can find more details and updates in the docs here: https://ai.google.dev/gemini-api/docs/live-tools#combine-tools

Thanks

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5

Any ETA on this? Or have you already fixed it with recent releases?

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