[BUG] claude-in-chrome: tabs_context_mcp({createIfEmpty: true}) places new tab in an existing unrelated window instead of creating an isolated one

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

I asked Claude Code to open a Chrome Tab for use in further work we'd be doing. The setting createIfEmpty: true is being used, but instead of opening a fresh Chrome WINDOW to place the tab, it appended the tab to a prior existing Chrome WINDOW that previously had ZERO Claude Chrome tabs in it.

Actual behavior: The new tab was instead appended to an existing, unrelated Chrome window that already had 16 non-Claude tabs open in it, rather than opening in a fresh, isolated window.

Impact: Users who want to keep Claude/Claude Code-controlled tabs separate from their regular browsing windows can't rely on this — Claude tabs end up mixed into ordinary browsing windows, making them hard to locate among several other open windows.

Environment: Windows 11, Claude Code CLI, claude-in-chrome MCP extension.

Notes: There's no tool-level parameter to target a specific window on tab creation (tabs_create_mcp takes no arguments), so this can't currently be worked around from the calling side.

What Should Happen?

Expected behavior: Per the tool's own description, calling tabs_context_mcp with createIfEmpty: true when no MCP tab group exists for the current session should "create a new Window with a new tab group containing an empty tab."

Error Messages/Logs

Steps to Reproduce

Open a Chrome browser window, open a number of tabs.
Start claude code
Tell claude to open a Chrome tab to user for future work in the session
The claude tab will open in the existing window intsead of a fresh, new one.

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.236

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_