feat: add agent buider tools to docs (#1152)

## Overview
Adds the agent builder tools that are available to docs.

## Type of change

**Type:** [Replace with: New documentation page / Update existing
documentation / Fix typo/bug/link/formatting / Remove outdated content /
Other]

## Related issues/PRs
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- GitHub issue:
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## Checklist
<!-- Put an 'x' in all boxes that apply -->
- [ ] I have read the [contributing guidelines](README.md)
- [ ] I have tested my changes locally using `docs dev`
- [ ] All code examples have been tested and work correctly
- [ ] I have used **root relative** paths for internal links
- [ ] I have updated navigation in `src/docs.json` if needed
- I have gotten approval from the relevant reviewers
- (Internal team members only / optional) I have created a preview
deployment using the [Create Preview Branch
workflow](https://github.com/langchain-ai/docs/actions/workflows/create-preview-branch.yml)

## Additional notes
<!-- Any other information that would be helpful for reviewers -->

---------

Co-authored-by: Lauren Hirata Singh <lauren@langchain.dev>

Author: Palashio

src/docs.json

@@ -1298,7 +1298,8 @@
             "tab": "Agent Builder",
             "pages": [
               "langsmith/agent-builder",
-              "langsmith/agent-builder-setup"
+              "langsmith/agent-builder-setup",
+              "langsmith/agent-builder-tools"
             ]
           },
           {

src/langsmith/agent-builder-tools.mdx

@@ -0,0 +1,100 @@
+---
+title: Supported tools
+sidebarTitle: Tools
+mode: wide
+---
+
+Use these built-in tools to give your agents access to email, calendars, chat, project management, search, social, and general web utilities.
+
+<Callout icon="circle-info" color="#DCFCE7" iconType="regular">
+  Google, Slack, Linear, and LinkedIn use OAuth. Exa, Tavily, and Twitter/X use workspace secrets.
+</Callout>
+
+<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="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>
+
+  <div style={{ position: 'relative' }}>
+    <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="LinkedIn" icon="linkedin">
+    Post to profile
+    <ul>
+      <li>Publish a post with optional image or link</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="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>
+
+  <div style={{ position: 'relative' }}>
+    <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="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>