Google Released February 25, 2026 Synced Mar 10, 2026

Google: Gemini 3.1 Pro Preview Custom Tools

Gemini 3.1 Pro Preview Custom Tools is a variant of Gemini 3.1 Pro that improves tool selection behavior by preventing overuse of a general bash tool when more efficient third-party or user-defined functions are available. This specialized preview endpoint significantly increases function calling reliability and ensures the model selects the most appropriate tool in coding agents and complex, multi-tool workflows. It retains the core strengths of Gemini 3.1 Pro, including multimodal reasoning across text, image, video, audio, and code, a 1M-token context window, and strong software engineering performance.

Tool useVisionAudioReasoning

Why it stands out

Offers a 1049K-token context window, enabling full-document and multi-file analysis without chunking.

Combines tool use with reasoning — a strong baseline for agentic and multi-step workflows.

Multimodal input (vision and audio) extends it beyond text-only workflows.

What to watch

No benchmark score currently tracked — evaluate using task-specific testing alongside pricing and capability data.

Release timeline

Tracked events for Google: Gemini 3.1 Pro Preview Custom Tools.

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release

Google: Gemini 3.1 Pro Preview Custom Tools entered the tracked catalog

February 25, 2026

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Recent changes

LaunchFeb 25

Google launched Google: Gemini 3.1 Pro Preview Custom Tools

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