What
When the navigate tool is called with a URL but no tabId, Claude in Chrome now automatically issues a tabs_context_mcp call in the background to acquire a tab, then injects the tab context into the result. The caller no longer needs to call tabs_context_mcp first for simple URL navigation.
Details
- A short timeout bounds the background lookup; if it exceeds the limit, the tool returns an error instructing the caller to retry or call
tabs_context_mcpexplicitly. url: "back"andurl: "forward"still require an explicittabId(they have no meaningful default).- The tab context JSON (from the front-loaded lookup) is appended to the successful navigate result for reference.
Evidence
Auto tab lookup logic (search for "The hidden tabs_context_mcp lookup did not respond within")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.