You'll noticeTier: how much it should matter to you
4Useful: my rating, 1 to 5
3Signal: worth watching, 1 to 5
MCPArea: what it touches
ImprovementsKind: in v2.1.307,
What probably matters to youSection of the release
What
Some MCP tools (tools provided by outside services, such as uploading a file to Drive) take a reference to a file on your computer. Before, only that reference was held when you were asked to approve the call, and the file was read later when it was sent. A tool can now be configured with approvalSeesContent:
The file is read when the call is checked, and its content is filled in (base64 encoded, a text form of the file) so the approval prompt and the auto-classifier (the automatic reviewer used in auto mode) see the content or the reference.
The original reference is put back for the record of the tool call.
The call then reuses that content instead of reading the file again when sending.
The tool's MCP information is marked with remoteFileReferenceFill: true.
The size of the stored content is kept within limits.
Why
When you approve a file upload, you can see what is actually being sent, and what is sent is the same content you approved rather than a fresh read of the file.
