Building a Research Agent with Gemini 3 + Deep Agents

Model Performance - Gemini 3 demonstrates extremely strong performance across various benchmarks, achieving state-of-the-art results in multiple areas [1] - Gemini 3 excels in tasks relevant to building agents, particularly in long horizon planning (Vending bench 2), terminal-based coding (Terminal Bench 2), and real-world contextual tasks like customer support (Sierra Tow Squared Bench) [2][3] Deep Agent Harness & Tool Utilization - The Deep Agent harness, an open-source tool, is used to test Gemini 3's agent-building capabilities, featuring built-in tools for planning, sub-agent delegation, and file system manipulation [3][4] - Gemini 3 effectively utilizes native tools within the Deep Agent harness, including file manipulation, planning, and sub-agent delegation, for tasks like research [18] - The agent successfully plans tasks, writes files, initiates sub-agents, analyzes results, updates to-dos, and generates final reports with citations [7][8] Research Task & Workflow - A research task is implemented using Gemini 3 within the Deep Agent harness, demonstrating the model's ability to perform complex tasks [5] - The research agent workflow involves creating to-dos, writing the research request to a file, initiating a sub-agent for research, analyzing results, and writing a final report [6][7] - The agent effectively uses a custom research sub-agent to isolate context, conduct in-depth research, and return results to the parent agent [15] Implementation & Customization - Gemini 3 can be easily integrated into existing workflows using Langchain and the Deep Agent harness [12][13] - The Deep Agent harness allows for customization through custom tools, instructions, and sub-agents, enabling users to tailor the agent to specific use cases [4][11] - The provided quick start repository offers instructions and code for running Gemini 3 with the Deep Agent harness, facilitating experimentation and customization [9][10]