MCP reconnect causes AI to hang waiting for ToolSearch instead of proceeding

Bug Description

After an MCP server reconnects (stdio transport), Claude Code receives a system reminder:

The following deferred tools are now available via ToolSearch. Their schemas are NOT loaded — calling them directly will fail with InputValidationError.

The AI then stops working entirely and waits for the user to confirm before calling ToolSearch. When the user asks "what's happening?", the AI responds:

"I need to call ToolSearch to reload tool schemas after MCP reconnection. I'm waiting for your approval."

But it never actually calls ToolSearch or proceeds. The user must press ESC and type "proceed" to unstick it.

Expected Behavior

The AI should automatically call ToolSearch to reload the schemas and continue working without user intervention. The deferred tools system reminder should not cause the AI to pause and wait.

Steps to Reproduce

1. Open Claude Code in a project with an MCP server (stdio transport)
2. Start working with MCP tools (e.g., mcp__my-server__my_tool)
3. The MCP server disconnects and reconnects (e.g., process restart, network issue)
4. Claude Code receives the "deferred tools available" system reminder
5. The AI stops working and appears to be "thinking" indefinitely
6. User types anything → AI says it needs to do ToolSearch first but doesn't do it
7. Only ESC + "proceed" unsticks it

Environment

• Claude Code on Windows 11 (also tested on desktop app)
• Model: claude-opus-4-7 (1M context)
• MCP server: custom stdio transport (.NET)
• Permission mode: bypassPermissions
• Multiple MCP servers registered (bia-ws, chrome-devtools, firecrawl, microsoft-learn, Google Calendar/Gmail/Drive)

Impact

This is a significant workflow blocker when using MCP tools. Any MCP reconnection (which can happen due to server updates, network issues, or PC sleep/wake) causes the AI to become unresponsive until manually unstuck. Users lose work context and must restart conversations.

Workaround

Press ESC to interrupt, then type "proceed" or "vai" (any text). The AI then calls ToolSearch and resumes. But this breaks the workflow every time MCP reconnects.