<!--
name: 'Tool Description: WebFetch'
description: Default SDK built-in tool description and input schema for WebFetch.
sdkPackage: '@anthropic-ai/claude-agent-sdk@0.3.168'
claudeCodeVersion: '2.1.168'
tool: "WebFetch"
-->
# Tool Description: WebFetch

## Metadata

- Request location: `tools[]`
- Tool name: `WebFetch`
- Input schema properties: `url`, `prompt`

## Description

Fetches a URL, converts the page to markdown, and answers `prompt` against it using a small fast model.

- Fails on authenticated/private URLs — use an authenticated MCP tool or `gh` for those instead.
- HTTP is upgraded to HTTPS. Cross-host redirects are returned to you rather than followed; call again with the redirect URL.
- Responses are cached for 15 minutes per URL.

## Input Schema

```json
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "url": {
      "description": "The URL to fetch content from",
      "type": "string",
      "format": "uri"
    },
    "prompt": {
      "description": "The prompt to run on the fetched content",
      "type": "string"
    }
  },
  "required": [
    "url",
    "prompt"
  ],
  "additionalProperties": false
}
```

## Token Impact

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- Complete definition estimated tokens: **283**
- Measurement: captured tool object serialized independently as JSON text against the common baseline
- Additivity: independent, non-additive estimate
<!-- TOKEN_COUNT_END -->