[FEATURE] Tool call to manage VS Code workspace folders (add/remove/list) from a running Claude Code session

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

There is no tool available to a Claude Code session that can ask the connected IDE (VS Code / code-server, via the extension's own MCP/IDE channel) to perform workspace-level actions — e.g. "add this folder to the current workspace", "remove this folder", "list open workspace folders". The only IDE-adjacent tool currently exposed is LSP (code intelligence: goToDefinition, findReferences, hover, etc.) — nothing for workspace/window state.

This came up in a session where I'd split a subfolder of an existing repo into its own standalone repo, and needed to add the new location as a folder in an existing multi-root .code-workspace file. I asked "can't you just ask VS Code directly?", and the answer was no — the only available path was to locate the right .code-workspace JSON file on disk and edit its folders array directly with a text-editing tool.

That workaround has real downsides:

• It requires knowing/finding the right .code-workspace file — not always obvious when multiple workspace files exist across synced/local paths (e.g. a repo-local copy vs. a OneDrive-synced copy).
• It bypasses the running VS Code window entirely: if the window has unsaved/in-memory workspace state, or the change needs to take effect without a manual reload, a direct file edit doesn't trigger VS Code's own onDidChangeWorkspaceFolders handling.
• It's the kind of action a user would naturally expect their IDE assistant to just "do", the same way the extension's own "Add Folder to Workspace..." command does it live.

Proposed Solution

Expose an IDE-integration tool (via the same channel the extension already uses for the ide MCP server / lock-file protocol) that lets Claude:

• addWorkspaceFolder(path) / removeWorkspaceFolder(path) — mirrors VS Code's own vscode.workspace.updateWorkspaceFolders API.
• listWorkspaceFolders() — so Claude can check current state before acting instead of guessing from disk.

This would let Claude Code perform the same "add folder to workspace" action a user would do via the Command Palette, without needing to find and hand-edit the .code-workspace file — and it would take effect immediately in the running window.

Alternative Solutions

Keep editing the .code-workspace file directly on disk (current behavior). Works, but has the downsides described above.

Priority

Nice to have

Feature Category

IDE Integration

Use Case Example

1. User splits a subfolder into its own repo and asks Claude to add it to the current multi-root workspace.
2. Claude calls listWorkspaceFolders() to see current state, then addWorkspaceFolder(newPath).
3. VS Code updates the workspace live, no manual file edit or reload needed.

Additional Context

_No response_