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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

ToolSearch

tool in the build JSON

A Claude Code tool, read out of the shipped bundle. It has been in the build since v2.1.263, including the newest one read.

Browser automation now loads the tab-closing tool up front, so Claude can tidy tabs without another lookup.

Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.221.

First seen v2.1.263 6 Sep 2026
Last seen v2.1.280 22 Sep 2026
Builds16 / 123on this box, as of v2.1.280
Written about v2.1.14 first named in a changelog, 20 Jan 2026
v2.1.263in the build not in the build never minedv2.1.280

In the changelogs

17

Releases whose published page names ToolSearch.

  1. v2.1.280
    The main system prompt in the reminder-toolsearch-deferred prompt was rewritten

    The reminder-toolsearch-deferred prompt was rewritten with guidance to finish the whole task before reporting done

    found in this entry's text

  2. v2.1.265
    late-tool-additions rejection message now also mentions inline-tools fallback

    Rejected late-tool-addition warning now also mentions falling back to inline tools

    found in this entry's text

  3. v2.1.257
    MCP late tool-addition rejections now sticky-reject a beta until /clear or /compact

    When an MCP server rejects a late tool addition, the beta stays rejected until you run /clear or /compact.

    found in this entry's text

  4. v2.1.257
    ToolSearchTool now scopes MCP tool filtering by agent/session betas

    ToolSearch now filters the tool pool per agent and session betas before running its search.

    named in this entry, found in this entry's text

  5. v2.1.221
    Chrome browser core ToolSearch batch includes tab closing

    Browser automation now loads the tab-closing tool up front, so Claude can tidy tabs without another lookup.

    found in this entry's text

  6. v2.1.221
    Tool search refused for pre-4.5 models on Vertex

    Fixes older Vertex models erroring on tool search; they now just load MCP tools normally.

    found in this entry's text

  7. v2.1.206
    EndConversation Tool [Feature-Flagged]

    found in this entry's text

  8. v2.1.172
  9. v2.1.163
    /reload-plugins Cache Impact Warning

    found in this entry's text

  10. v2.1.70
  11. v2.1.69
    ToolSearch Multi-Select and Search Hints

    found in this entry's text

  12. v2.1.64
    ToolSearch Multi-Select

    found in this entry's text

  13. v2.1.61
  14. v2.1.51
    Smart Tool Deferral [Gradual Rollout]

    found in this entry's text

  15. v2.1.50
  16. v2.1.19
    Improved ToolSearch Documentation

    found in this entry's text

  17. v2.1.14
    ToolSearch (renamed from MCPSearch)

    found in this entry's text

First cited

5

The earliest release whose published evidence quoted ToolSearch was v2.1.70, 6 Mar 2026. That is the oldest release this project wrote about it, so it is a floor on the name's age and not the release that introduced it. It is not a presence reading: which builds carried the name is the table below.

ReleaseDateThe span that was quoted
v2.1.706 Mar 2026[ToolSearch:optimistic] disabled: ANTHROPIC_BASE_URL=
v2.1.17210 Jun 2026batch every tool you expect to need into ONE ToolSearch call
v2.1.2069 Jul 2026Load the full guidance via ToolSearch
v2.1.2571 Sep 2026falling back to the ToolSearch announcement, sticky-rejecting the beta until /clear or /compact
v2.1.2658 Sep 2026falling back to the ToolSearch announcement (or to inline tools where there is no ToolSearch), sticky-rejecting the beta until /clear or /compact

Presence across releases

1
BuildsHow manyDatesReading
v2.1.263 – v2.1.28016 builds6 Sep 2026 → 22 Sep 2026 in the build

Build by build

16

One row per release since the first build this name was read out of. Absent means the build was read and the name was not in it, never mined means no bundle for that release was ever archived, and a declared type or a default is only ever what that release's own bundle stated.

BuildDateStateThe record behind it
v2.1.2636 Sep 2026·addedverdict: added
v2.1.2658 Sep 2026·presentverdict: present
v2.1.2668 Sep 2026·presentverdict: present
v2.1.2679 Sep 2026·presentverdict: present
v2.1.26810 Sep 2026·presentverdict: present
v2.1.26911 Sep 2026·presentverdict: present
v2.1.27012 Sep 2026·presentverdict: present
v2.1.27114 Sep 2026·presentverdict: present
v2.1.27214 Sep 2026·presentverdict: present
v2.1.27315 Sep 2026·presentverdict: present
v2.1.27416 Sep 2026·presentverdict: present
v2.1.27517 Sep 2026·presentverdict: present
v2.1.27618 Sep 2026·presentverdict: present
v2.1.27718 Sep 2026·presentverdict: present
v2.1.27819 Sep 2026·presentverdict: present
v2.1.28022 Sep 2026·presentverdict: present

Read out of the published npm bundle release by release, and out of Anthropic's own documentation as this site captured it. Nothing on this page is a description anybody here wrote about what the tool does. All tools.

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