name: ADK Tools description: This skill should be used when the user asks about "adding a tool", "FunctionTool", "creating tools", "MCP integration", "OpenAPI tools", "built-in tools", "google_search tool", "code_execution tool", "long-running tools", "async tools", "third-party tools", "LangChain tools", "computer use", or needs guidance on extending agent capabilities with custom functions, API integrations, or external tool frameworks. version: 3.0.0

ADK Tools

Guide for extending agent capabilities with tools. Covers custom functions, API integrations, and external frameworks.

When to Use

Adding custom Python functions as tools
Integrating external APIs
Connecting MCP servers
Using built-in ADK tools
Handling long-running operations
Computer use capabilities
LangChain/LlamaIndex tool integration

When NOT to Use

Initial project setup → Use @adk-core instead
Creating agents → Use @adk-core instead
Multi-agent coordination → Use @adk-orchestration instead
Security policies → Use @adk-production instead

Key Concepts

FunctionTool wraps Python functions into agent-callable tools. Docstrings become tool descriptions, type hints define parameters.

Built-in Tools like google_search and code_execution are pre-configured and ready to use via tool name.

MCP Integration connects Model Context Protocol servers as tool sources. Configure in adk.yaml or via .mcp.json.

OpenAPI Tools auto-generate from API specifications. ADK creates typed tools from your OpenAPI schemas.

Long-Running Tools use async patterns or callbacks for operations that exceed typical timeouts.

Computer Use Tools provide screen, keyboard, and mouse control for desktop automation tasks.

Third-Party Frameworks like LangChain and LlamaIndex expose their tool ecosystems to ADK agents.

Implementation Pattern

from adk.tools import FunctionTool
from adk import LlmAgent

def calculate_area(length: float, width: float) -> float:
    """Calculate rectangle area."""
    return length * width

area_tool = FunctionTool(calculate_area)
agent = LlmAgent(tools=[area_tool])

References

Detailed guides with code examples:

references/tools-function.md - Custom Python tools
references/tools-builtin.md - Pre-configured tools
references/tools-mcp.md - MCP server integration
references/tools-openapi.md - OpenAPI schemas
references/tools-async.md - Long-running operations
references/tools-computer-use.md - Desktop automation
references/tools-third-party.md - LangChain/LlamaIndex