ADK Tools

Types of tools

  • Function Tools
    • Python functions
    • Agents-as-tools — wrap an agent as a tool (see ADK-Multi-Agent for AgentTool)
    • Long-running function tools
  • Built-in Tools (only work with Gemini; import to use)
    • Google search, code execution, RAG (ready-to-use)
  • Third-party Tools
    • LangChain tools, CrewAI tools

Best practices

  • When returning a result, be as instructional and specific as possible for the agent consuming it. A dictionary often works well.
  • Use a docstring to explain the tool to the agent — the agent reads it for tool selection.
  • Be in the correct directory when running.

See next