Develop your own ADK agent

We provide two sample Google Agent Development Kit-based agents you can use as inspiration for building your own agent:

• Try Data Commons MCP Tools with a Custom Agent is a Google Colab tutorial that shows how to build an ADK Python agent step by step.
• The sample basic agent is a simple Python Google ADK agent you can use to develop locally.

Customize the sample agent

You can make changes directly to the Python files in https://github.com/datacommonsorg/agent-toolkit/blob/main/packages/datacommons-mcp/examples/sample_agents/basic_agent/. You’ll need to restart the agent any time you make changes.

Tip: You do not need to install the Google ADK; when you use the command we provide to start the agent, it downloads the ADK dependencies at run time.

Customize the model

To change to a different LLM, edit the AGENT_MODEL constant in packages/datacommons-mcp/examples/sample_agents/basic_agent/agent.py.

Customize agent behavior

The agent’s behavior is determined by prompts provided in the AGENT_INSTRUCTIONS in packages/datacommons-mcp/examples/sample_agents/basic_agent/instructions.py.

You can add your own prompts to modify how the agent handles tool results. For example, you might want to give a prompt to “build a report for every response” or “always save tabular results to a CSV file”. See the Google ADK page on LLM agent instructions for tips on how to write good prompts.

Page last updated: October 24, 2025 • Send feedback about this page