[BUG] Custom mcpb is not picked up by Claude in cowork

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?

When connecting a new mcpb bundle in cowork and requesting Claude perform some action, it does not see the connector unless prompted. Example, create a custom mcpb called "Custom Gmail". Enable this on cowork. Ask Claude to review the email information it has access to. Claude will search marketplace and look for tools but not find the mcpb.

What Should Happen?

Claude should find the mcpb connector and not default to searching the marketplace without checking its locally installed bundles.

Error Messages/Logs

Steps to Reproduce

1. Create and install a custom mcpb, particularly one that overlaps with a function on the marketplace. For example, Custom - Glean or Custom - Gmail
2. Ask Claude Cowork to exercise some functionality of the local bundle
3. Cowork will not use the bundle unless prompted

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Claude Cowork

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_