WebFetch tool description
CLI Claude Code, interactive mode, v2.1.291. The text the model is given for this tool, line by line, with each line marked against the previous capture taken the same way. 15 model strings share this prompt, byte for byte.
Lines211,608 characters
Moved+0−0 against v2.1.290
Sent to15model strings get this description
Copies2distinct descriptions under this name
Parameters32 of them required
Every tool→every description on this arm
2 genuinely different descriptions of this tool
Plain text · sha256 d3dc99188f10
The description, line by line
21 lines Line numbers are v2.1.290 on the left and this capture on the right.
1
1
IMPORTANT: WebFetch WILL FAIL for authenticated or private URLs. Before using this tool, check if the URL points to an authenticated service (e.g. Google Docs, Confluence, Jira, GitHub). If so, look for a specialized MCP tool that provides authenticated access.
2
2
3
3
- Fetches content from a specified URL and processes it using an AI model
4
4
- Takes a URL and a prompt as input
5
5
- Fetches the URL content, converts HTML to markdown
6
6
- Processes the content with the prompt using a small, fast model
7
7
- Returns the model's response about the content
8
8
- Use this tool when you need to retrieve and analyze web content
9
9
10
10
Usage notes:
11
11
- IMPORTANT: If an MCP-provided web fetch tool is available, prefer using that tool instead of this one, as it may have fewer restrictions.
12
12
- The URL must be a fully-formed valid URL
13
13
- HTTP URLs will be automatically upgraded to HTTPS
14
14
- localhost and other hostnames without a dot are not supported; for a local server, use curl via Bash
15
15
- The prompt should describe what information you want to extract from the page
16
16
- This tool is read-only and does not modify any files
17
17
- Results may be summarized if the content is very large
18
18
- Includes a self-cleaning cache (entries expire after 15 minutes) for faster responses when repeatedly accessing the same URL
19
19
- When a URL redirects to a different host, the tool will inform you and provide the redirect URL in a special format. You should then make a new WebFetch request with the redirect URL to fetch the content.
20
20
- For GitHub URLs, prefer using the gh CLI via Bash instead (e.g., gh pr view, gh issue view, gh api).
21
21
What it accepts
3 parameters The JSON parameter schema sent beside this description, 646 characters of it. Name, type, then whether the client marked it required.offset
integer
optional
Character position in the page text to start reading from. Use it to read on through a page too long for one call, with the value the previous result gave.
prompt
string
required
The prompt to run on the fetched content
url
string
required
The URL to fetch content from
sha256 1e11868da446 · the schema as the client sent it:
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"properties": {
"offset": {
"description": "Character position in the page text to start reading from. Use it to read on through a page too long for one call, with the value the previous result gave.",
"maximum": 9007199254740991,
"minimum": 0,
"type": "integer"
},
"prompt": {
"description": "The prompt to run on the fetched content",
"type": "string"
},
"url": {
"description": "The URL to fetch content from",
"format": "uri",
"type": "string"
}
},
"required": [
"url",
"prompt"
],
"type": "object"
}