Tool-use permission requests can now be tagged tool_kind: "browser" so SDK hosts can route browser tools to a specialized UI
What
The tool-use permission request payload (the can_use_tool control-protocol message) gained an optional tool_kind field, currently only ever set to "browser". This lets SDK hosts — such as Claude in Chrome, Cowork, Claude Desktop, or Remote Devices — recognize browser-related tool calls and show a specialized permission prompt for them, instead of having to guess by matching the tool's name. The field is now actually populated (tool_kind: "browser") on real requests, not just declared in the schema.
Why Browser tools often need a different kind of approval UI than regular tools. Tagging them explicitly lets host applications build that UI reliably instead of relying on fragile name-matching.