---
title: "Tool: definition and example | Agent MCP Directory"
description: "Tool: A function an MCP server offers for the model to call, with a name, description and input schema. Defined with a sourced example."
canonical: https://agentmcpdirectory.com/glossary/mcp-tool
site: "Agent MCP Directory"
last_updated: 2026-11-04
section: "Glossary"
---

# Tool: definition and example | Agent MCP Directory

> Tool: A function an MCP server offers for the model to call, with a name, description and input schema. Defined with a sourced example.

Source: https://agentmcpdirectory.com/glossary/mcp-tool
Site: Agent MCP Directory
Last reviewed: 2026-11-04

# Tool

Tool: A function an MCP server offers for the model to call, with a name, description and input schema. Example: Browserbase's tools are navigate, act, observe, extract, start and end. Next in the glossary is Tool annotations: Hints on a tool such as readOnlyHint and destructiveHint that tell clients how risky a call is.

## Definition

A function an MCP server offers for the model to call, with a name, description and input schema.

## Example, with source

Browserbase's tools are navigate, act, observe, extract, start and end. ([docs.browserbase.com](https://docs.browserbase.com/integrations/mcp/setup), read 4 November 2026)

## Where it appears on this site

-   [MCP](https://agentmcpdirectory.com/standards/mcp/)
-   [Tool descriptions and agent success](https://agentmcpdirectory.com/guides/tool-descriptions-and-agent-success/)

## Neighbouring terms

-   [Tasks extension](https://agentmcpdirectory.com/glossary/tasks-extension/): An official MCP extension for long-running operations with polling and durable handles, moved out of core in 2026-07-28.
-   [Tool annotations](https://agentmcpdirectory.com/glossary/tool-annotations/): Hints on a tool such as readOnlyHint and destructiveHint that tell clients how risky a call is.
-   [WebMCP](https://agentmcpdirectory.com/glossary/webmcp/): A draft browser API for pages to register JavaScript tools that an in-browser agent can call.

Edition

4 November 2026

Method

[How rows are verified](https://agentmcpdirectory.com/method/)

Data

[CSV and JSON](https://agentmcpdirectory.com/data/)

Markdown

[This page as markdown](https://agentmcpdirectory.com/glossary/mcp-tool/index.md)

## Sources

-   [Source for the Tool example](https://docs.browserbase.com/integrations/mcp/setup), read 4 November 2026

Last reviewed 4 November 2026