Feature Request: Dynamic MCP Server Loading/Unloading

Problem

MCP tool definitions consume significant context tokens (~14.5k for Honeycomb MCP) even when not actively used. In long sessions, this reduces available context for actual work.

Current Behavior

• MCP servers are loaded at session startup based on configuration
• They remain active for the entire session
• No way to toggle servers on/off mid-session

Proposed Solution

Add ability to dynamically enable/disable MCP servers during a session:

Option A: Slash command

/mcp disable honeycomb
/mcp enable honeycomb

Option B: On-demand loading
Only load MCP tool definitions when first invoked, not at startup

Option C: Lazy tool registration
Register tools but defer sending definitions to API until tool is requested

Benefits

• Significant context savings for sessions that occasionally need MCP
• Better token budget management for complex tasks
• Users can load specialized MCPs only when entering that workflow

Workaround

Currently requires removing/re-adding servers between sessions, which is impractical.