Google: Gemini 3.1 Pro Preview Custom Tools
Gemini 3.1 Pro Preview Custom Tools shares the same pricing and context window as the benchmarked Gemini 3.1 Pro Preview, but as a variant without its own benchmark data it cannot inherit the parent model's scores — it may be useful for specific tool-calling workflows but cannot be rated as a top-tier model independently.
Assessment date: March 14, 2026
Our methodology takes into account a range of factors including pricing, functionality, capabilities, benchmark performance, and real-world applicability. Rankings are reviewed and updated regularly as new models are released. Issues with our rankings? Contact us
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.
Capabilities
Architecture
| Modality | Text + Image + File + Audio + Video → Text |
| Tokenizer | Gemini |
Model Information
Pricing
| Token Type | Cost per 1M tokens | Cost per 1K tokens |
|---|---|---|
| Input | $2.00 | $0.002000 |
| Output | $12.00 | $0.012000 |
Live Performance
Live endpoint metrics — refreshed every 30 minutes.
