[BUG] Cowork April 9-10 plugin migration dropped Gamma connector — Gamma tools unavailable in all Cowork sessions

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?

Since the Cowork plugin system migration on approximately April 9-10 2026, the Gamma connector (mcp__2403d7fc-c438-4817-ae7a-934495eed140) is no longer available inside any Cowork session.

Prior to the migration, Cowork sessions were spawned with a direct --mcp-config JSON that included all connector UUIDs including Gamma. After the migration, Cowork sessions switched to a plugin-based system using --plugin-dir flags, loading 6 knowledge-work plugins from the marketplace. Gamma was not included in any of those plugins, so it silently disappeared.

Canva survived the migration because it has a slot in the marketing plugin (plugin_01XH8yMVJbQydrVkX6WgLvck). Gamma, despite being the same category of connector (design/presentation), has no plugin home and is now completely absent from Cowork.

The connector still shows as connected in Claude Desktop's main connector list (toolCount: 4, status: connected), and Gamma tools work correctly in Claude Code CLI sessions. The breakage is isolated to Cowork.

What Should Happen?

Gamma tools (generate, get_themes, get_generation_status, get_folders, read_gamma) should be available inside Cowork sessions, as they were before the April 9-10 plugin migration.

Either:

• Gamma should be added to one of the existing knowledge-work plugins (e.g. the marketing plugin alongside Canva), or
• A dedicated plugin for standalone connectors like Gamma should be created

The Always allow permission toggle in Claude Desktop has no effect on this issue — the problem is that the tool is never registered in the Cowork environment at all, not that it lacks permission.

Error Messages/Logs

When calling any Gamma tool in Cowork: "No such tool available"

From cowork_vm_node.log — every Cowork spawn since April 10 shows NO --mcp-config and only these --plugin-dir entries:
  plugin_018pLNd4CGF8vEEmyztWR7fi (cowork-plugin-management)
  plugin_01GC5sHmfRpUwySPemYHW7n5 (engineering)
  plugin_01S5vijNgfCWGfVaeNbYCdNz (operations)
  plugin_01MDPHx1gWYn4qF2NfPQJSM1 (legal)
  plugin_01XH8yMVJbQydrVkX6WgLvck (marketing — contains Canva but NOT Gamma)
  plugin_01LE8tT9qAeeXKkpJ3yvTHUM (customer-support)

From main.log — most recent session (April 14) confirms Gamma IS registered in the Desktop process:
  { "name": "2403d7fc-c438-4817-ae7a-934495eed140", "status": "connected", "toolCount": 4 }

But zero Gamma tool calls appear anywhere in cowork_vm_node.log — the tool simply does not exist inside the VM.

Steps to Reproduce

1. Connect the Gamma connector in Claude Desktop (Settings → Connectors)
2. Open a Cowork session
3. Ask Claude to use Gamma to generate a presentation (e.g. "Use Gamma to create a slide deck about X")
4. Claude either says it cannot find Gamma tools, or any direct tool call to mcp__2403d7fc-c438-4817-ae7a-934495eed140__generate returns "No such tool available"

Note: The same Gamma connector works correctly in a Claude Code CLI session in the same environment — the issue is specific to Cowork's plugin-based session spawner.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Before April 9, 2026 (Claude Desktop — Cowork plugin migration)

Claude Code Version

2.1.107 (Claude Code) — Claude Desktop Windows app (Claude_pzs8sxrjxfjjc)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

Platform: Claude Desktop (Windows, app package Claude_pzs8sxrjxfjjc)
OS: Windows 11

Timeline:

• Before ~April 9: Cowork spawned with --mcp-config {"2403d7fc-c438-4817-ae7a-934495eed140":{"type":"sdk",...}} — Gamma worked
• April 9-10: Plugin manifest last updated ("updatedAt": "2026-04-09T23:44:45.863519Z")
• April 10+: All Cowork spawns use only --plugin-dir flags, no --mcp-config, Gamma gone

Why Always allow doesn't fix it:** The permission system only gates tool calls that are already registered. Since Gamma is never loaded into the Cowork VM's MCP server list, no permission prompt is ever emitted for it.

Suggested fix:** Add Gamma to plugin_01XH8yMVJbQydrVkX6WgLvck (marketing plugin) alongside Canva, or restore standalone connector injection via --mcp-config for connectors not covered by a plugin.