Agent Tool

The AgentTool allows you to treat an entire BaseAgent as a callable tool, forming the basis of hierarchical agent orchestration.

Overview

By wrapping a specialized sub-agent in an AgentTool, a "coordinator" agent can delegate complex tasks. The LLM decides to invoke the sub-agent just like any other function.

Usage

Instantiate a sub-agent, wrap it, and add it to the parent agent's Tools list.

using GoogleAdk.Core.Agents;
using GoogleAdk.Core.Tools;

// 1. Create specialized sub-agent
var codingAgent = new LlmAgent(new LlmAgentConfig
{
    Name = "coder",
    Model = "gemini-2.5-pro",
    Instruction = "Write pristine C# code. Do not explain, only code."
});

// 2. Create the coordinator
var coordinatorAgent = new LlmAgent(new LlmAgentConfig
{
    Name = "coordinator",
    Model = "gemini-2.5-flash",
    Instruction = "You are a tech lead. Use the 'coder' tool to generate code, then review it.",
    Tools = [ new AgentTool(codingAgent) ]
});

Flow

1. The coordinator decides it needs code and calls coder.
2. The ADK spins up an ephemeral runner for coder with the prompt.
3. The coder agent runs to completion.
4. The final response is returned to the coordinator as JSON.
5. The coordinator resumes execution with the code.