> ## Documentation Index
> Fetch the complete documentation index at: https://langchain-5e9cc07a-preview-export-1767976498-81c8aa9.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Tools

You can access a variety of tools in Agent Builder, including [built-in tools](#built-in-tools) and [tools from remote MCP servers](#remote-mcp-server-tools).

## Built-in tools

Use these built-in tools to give your agents access to email, calendars, chat, project management, code hosting, spreadsheets/BI, search, social, and general web utilities.

<Info icon="circle-info" color="#DCFCE7" iconType="regular">
  Google, Slack, Linear, GitHub, and LinkedIn use OAuth. Exa, Tavily, Pylon, and Twitter/X use workspace secrets (API keys).
</Info>

<CardGroup cols={2}>
  <Card title="Gmail" icon="google">
    Read and send email

    <ul>
      <li>Read emails (optionally include body, filter with search)</li>
      <li>Send email or reply to an existing message</li>
      <li>Create draft emails</li>
      <li>Mark messages as read</li>
      <li>Get a conversation thread</li>
      <li>Apply or create labels</li>
      <li>List mailbox labels</li>
    </ul>
  </Card>

  <Card title="Google Calendar" icon="google">
    Manage events

    <ul>
      <li>List events for a date</li>
      <li>Get event details</li>
      <li>Create new events</li>
    </ul>
  </Card>

  <Card title="Google Sheets" icon="google">
    Spreadsheets

    <ul>
      <li>Create spreadsheets</li>
      <li>Read ranges</li>
    </ul>
  </Card>

  <Card title="BigQuery" icon="database">
    Analytics

    <ul>
      <li>Execute SQL queries</li>
    </ul>
  </Card>

  <Card title="Slack" icon="slack">
    Send and read messages

    <ul>
      <li>Send a direct message to a user</li>
      <li>Post a message to a channel</li>
      <li>Reply in a thread</li>
      <li>Read channel history</li>
      <li>Read thread messages</li>
    </ul>
  </Card>

  <Card title="LinkedIn" icon="linkedin">
    Post to profile

    <ul>
      <li>Publish a post with optional image or link</li>
    </ul>
  </Card>

  <div style={{ position: 'relative', margin: 0, padding: 0 }}>
    <Card title="Twitter/X" icon="twitter">
      <ul>
        <li>Read a tweet by ID</li>
        <li>Read recent posts from a list</li>
      </ul>
    </Card>

    <div style={{ position: 'absolute', top: 16, right: 16 }}>
      <Tooltip tip="Required keys: TWITTER_API_KEY, TWITTER_API_KEY_SECRET">
        <Icon icon="key" size={16} />
      </Tooltip>
    </div>
  </div>

  <Card title="GitHub" icon="github">
    PRs, issues, and content

    <ul>
      <li>List pull requests</li>
      <li>Get pull request details</li>
      <li>Create issues and pull requests</li>
      <li>Comment on issues and pull requests</li>
      <li>Read repository files and list directories</li>
    </ul>
  </Card>

  <Card title="Linear" icon="list-check">
    Manage issues and teams

    <ul>
      <li>List teams and team members</li>
      <li>List issues with filters</li>
      <li>Get issue details</li>
      <li>Create, update, or delete issues</li>
    </ul>
  </Card>

  <Card title="Pylon" icon="list-check">
    Issue management

    <ul>
      <li>List issues</li>
      <li>Get issue details</li>
      <li>Update issues</li>
    </ul>
  </Card>

  <div style={{ position: 'relative', margin: 0, padding: 0 }}>
    <Card title="Search" icon="magnifying-glass">
      <ul>
        <li>Exa web search (optionally fetch page contents)</li>
        <li>Exa LinkedIn profile search</li>
        <li>Tavily web search</li>
      </ul>
    </Card>

    <div style={{ position: 'absolute', top: 16, right: 16 }}>
      <Tooltip tip="Exa: EXA_API_KEY; Tavily: TAVILY_API_KEY">
        <Icon icon="key" size={16} />
      </Tooltip>
    </div>
  </div>

  <Card title="Web utilities" icon="globe">
    <ul>
      <li>Read webpage text content</li>
      <li>Extract image URLs and metadata</li>
      <li>Notify user (for confirmations/updates)</li>
    </ul>
  </Card>
</CardGroup>

## Remote MCP server tools

Agent Builder can discover and use tools from remote [Model Context Protocol (MCP)](https://modelcontextprotocol.io/) servers. This lets you connect to external MCP servers and use their tools in your agents.

### How it works

* Agent Builder discovers tools from remote MCP servers via the standard MCP protocol.
* Headers configured in your workspace are automatically attached when fetching tools or calling them. Headers can be used for authentication.
* Tools from remote servers are available alongside built-in tools in Agent Builder.

### Configuration

Configure remote MCP servers in your LangSmith [workspace](/langsmith/administration-overview#workspaces):

1. Navigate to your workspace settings in the [LangSmith UI](https://smith.langchain.com).
2. Add your MCP server URL and any required headers (for example, `Authorization: Bearer {{MCP_TOKEN}}`).
3. Agent Builder automatically discovers tools from the server and applies the configured headers when calling tools.

<Note>
  Use workspace secret placeholders like `{{MCP_TOKEN}}` in headers. The platform resolves these from your workspace secrets at runtime.
</Note>

***

<Callout icon="pen-to-square" iconType="regular">
  [Edit this page on GitHub](https://github.com/langchain-ai/docs/edit/main/src/langsmith/agent-builder-tools.mdx) or [file an issue](https://github.com/langchain-ai/docs/issues/new/choose).
</Callout>

<Tip icon="terminal" iconType="regular">
  [Connect these docs](/use-these-docs) to Claude, VSCode, and more via MCP for real-time answers.
</Tip>