Crate adk_tool 

adk-tool

Tool system for ADK agents (FunctionTool, MCP, Google Search, AgentTool).

Overview

This crate provides the tool infrastructure for ADK agents:

• FunctionTool - Create tools from async Rust functions
• AgentTool - Use agents as callable tools for composition
• GoogleSearchTool - Web search via Gemini’s grounding
• McpToolset - Model Context Protocol integration
• BasicToolset - Group multiple tools together
• ExitLoopTool - Control flow for loop agents
• LoadArtifactsTool - Inject binary artifacts into context

Quick Start

use adk_tool::FunctionTool;
use adk_core::{ToolContext, Result};
use serde_json::{json, Value};
use std::sync::Arc;

async fn get_weather(ctx: Arc<dyn ToolContext>, args: Value) -> Result<Value> {
    let city = args["city"].as_str().unwrap_or("Unknown");
    Ok(json!({
        "city": city,
        "temperature": 72,
        "condition": "sunny"
    }))
}

let tool = FunctionTool::new(
    "get_weather",
    "Get current weather for a city",
    get_weather,
);

MCP Integration

Connect to MCP servers for external tools:

use adk_tool::McpToolset;
use rmcp::{ServiceExt, transport::TokioChildProcess};

let client = ().serve(TokioChildProcess::new(
    Command::new("npx")
        .arg("-y")
        .arg("@modelcontextprotocol/server-filesystem")
        .arg("/path/to/files")
)?).await?;

let toolset = McpToolset::new(client);

Re-exports

pub use builtin::ExitLoopTool;

pub use builtin::GoogleSearchTool;

pub use builtin::LoadArtifactsTool;

pub use mcp::McpToolset;

pub use toolset::string_predicate;

pub use toolset::BasicToolset;

Modules

builtin

mcp

toolset

Structs

AgentTool

AgentTool wraps an Agent to make it callable as a Tool.

AgentToolConfig

Configuration options for AgentTool behavior.

FunctionTool

Traits

Tool

ToolContext

Toolset