Gemini 3.1 Pro Preview Custom Tools
gemini-3.1-pro-preview-customtools
Google · chat · api · seen 13m ago
Preview
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Context
1M
Max output
65.5K
Input $/1M
$2.00
Output $/1M
$12.00
Modalities
text
Released
19 Feb 2026
AI summary
● machine-written
Google releases Gemini 3.1 Pro Preview Custom Tools
Gemini 3.1 Pro Preview Custom Tools is Google's frontier reasoning model supporting text input with a 1M-token context window and up to 65.5K token output. It is designed for advanced development, agentic systems, and complex workflows requiring multi-turn tool calling and autonomous task execution.
What's new
- Introduces MEDIUM thinking level to balance cost, speed, and performance
- Improved token efficiency across complex workflows
- Enhanced software engineering performance and agentic reliability
- Supports custom tools and efficient third-party functions
- Released February 19, 2026
Best for
Agentic coding and autonomous agentsFinancial modeling and spreadsheet automationMultimodal analysis and workflow automationHigh-context enterprise tasks requiring tool orchestration
Source: https://ai.google.dev/gemini-api/docs/models/gemini-3.1-pro-preview-customtools