Per-session MCP server profiles

Problem

MCP server connections are global -- toggling a server on/off affects all concurrent sessions. Different session types need different MCP servers:

• School/admin sessions need Google Workspace + Asana
• Code/research sessions need none (or just Playwright)
• Newsletter sessions need Constant Contact

With multiple concurrent sessions (common on Team plans), there's no way to optimize per session. Unneeded MCP tool schemas inflate the system prompt (~300 tokens per tool, ~50 tools for Google Workspace alone), increasing cost and -- on Windows -- correlating with higher surrogate bug bricking rates (#44230).

Proposed solution

Per-session or per-project MCP profiles. Possible approaches:

1. Project-level .claude/settings.json with an mcpServers section that overrides global connections
2. Named profiles (e.g., claude --mcp-profile school) that map to predefined server sets
3. Session-start flag (e.g., claude --mcp google-workspace,asana) to connect only specified servers

Workarounds tried

• ENABLE_TOOL_SEARCH=auto:5 defers some tools (Playwright, claude.ai integrations) but not locally-connected MCP servers like Google Workspace
• Manual /mcp toggling between sessions -- doesn't scale with concurrent sessions
• Accepting the overhead -- works but wastes ~4,000+ tokens/turn on sessions that don't need MCP

Environment

Windows 11, Team plan, Remote Control + CLI, typically 2-3 concurrent sessions.