Sweep 22 Sep 2026 · 17:19Z Build v2.1.280 501 read Stable v2.1.267 Latest v2.1.280 Next v2.1.280 Feeds RSS JSON llms.txt Unofficial
Tool description

WebSearch, as sent

SDK-CLI Agent SDK, print mode, v2.1.270. 17 model strings share this prompt, byte for byte.

Lines271,322 characters
Moved+0−0 against v2.1.269
Reach17model strings receive this description
Copies2distinct descriptions under this name
Parameters31 of them required Tools in captureall of themevery description on this arm
2 genuinely different descriptions of this tool Plain text · sha256 74921e4371b5

The description, rendered

This renders the markdown inside the description, so it isn’t quite the description itself.

The raw view and the plain text are the bytes as they were sent.

  • Allows Claude to search the web and use the results to inform responses
  • Provides up-to-date information for current events and recent data
  • Returns search result information formatted as search result blocks, including links as markdown hyperlinks
  • Use this tool for accessing information beyond Claude's knowledge cutoff
  • Searches are performed automatically within a single API call

CRITICAL REQUIREMENT - You MUST follow this:

  • After answering the user's question, you MUST include a "Sources:" section at the end of your response

  • In the Sources section, list all relevant URLs from the search results as markdown hyperlinks: Title

  • This is MANDATORY - never skip including sources in your response

  • Example format:

    [Your answer here]

    Sources:

Usage notes:

  • Domain filtering is supported to include or block specific websites
  • Web search is only available in the US

IMPORTANT - Use the correct year in search queries:

  • The current month is September 2026. You MUST use this year when searching for recent information, documentation, or current events.
  • Example: If the user asks for "latest React docs", search for "React documentation" with the current year, NOT last year

What it accepts

3 parameters The JSON parameter schema sent beside this description, 577 characters of it. Name, type, then whether the client marked it required.
allowed_domains string[] optional Only include search results from these domains
blocked_domains string[] optional Never include search results from these domains
query string required The search query to use

sha256 78ab127603dd · the schema as the client sent it:

{ "$schema": "https://json-schema.org/draft/2020-12/schema", "additionalProperties": false, "properties": { "allowed_domains": { "description": "Only include search results from these domains", "items": { "type": "string" }, "type": "array" }, "blocked_domains": { "description": "Never include search results from these domains", "items": { "type": "string" }, "type": "array" }, "query": { "description": "The search query to use", "minLength": 2, "type": "string" } }, "required": [ "query" ], "type": "object" }