[FEATURE] Allow connecting multiple Gmail accounts simultaneously via managed MCP servers

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

Currently, Claude.ai's managed MCP integrations (Gmail, Google Calendar, Slack, Atlassian, etc.)
only support connecting a single account per service. Many users — particularly those in
professional or managerial roles — work across multiple accounts daily (e.g., a personal Gmail
and a work Gmail, or multiple workspace Slack accounts).

There is no way to register multiple instances of the same managed MCP server with different
credentials, forcing users to manually disconnect and reconnect accounts when they need to switch
contexts. This breaks workflow continuity, especially in Claude Code sessions where users may
need to reference emails from one account while drafting in another, or monitor multiple Slack
workspaces simultaneously.

Proposed Solution

Users should be able to connect multiple accounts for the same MCP integration
(e.g., Gmail - Personal, Gmail - Work) and have Claude distinguish between them when executing
tool calls.

Alternative Solutions

_No response_

Priority

Medium - Would be very helpful

Feature Category

MCP server integration

Use Case Example

As a user,

I could connect to several gmail accounts (personal, professional), and ask Claude to read/clean/organize all of my emails

Additional Context

_No response_