Gemini 3.1 Pro Preview Custom Tools is a specialized variant of Google's flagship language model that takes a more disciplined approach to tool selection. Rather than defaulting to a generic bash tool when third-party or user-defined functions are available, this model variant has been tuned to recognize and select the most efficient tool for the task at hand. This refinement is particularly valuable for coding agents and complex multi-tool workflows where the difference between the right tool and the default tool can significantly impact reliability and performance.

The variant preserves the core multimodal reasoning capabilities of its parent model, handling text, images, video, audio, and code with strong software engineering performance. With access to an extensive that quick-info value window, it excels at maintaining coherence across long interactions and complex tasks. This specialized version is designed for developers building automation pipelines, coding assistants, and complex workflow agents that depend on precise tool selection.