MCP server extremely slow when analyzing project — hangs for minutes with no response

Description

When using codex mcp-server as an MCP tool in Claude Code (VSCode extension), the server takes an extremely long time to respond when asked to analyze a project. It hangs for several minutes with no output, eventually timing out or requiring manual cancellation.

Configuration

{
  "mcpServers": {
    "codex": {
      "type": "stdio",
      "command": "codex",
      "args": [
        "mcp-server",
        "-c", "model=gpt-5.3-codex",
        "-c", "reasoning_effort=high"
      ]
    }
  }
}

Environment

• OS: Windows 11
• Client: Claude Code (VSCode extension)
• Codex version: latest (installed via npm)
• Project size: ~200+ tracked files (Go board game engine, mixed C++/Java/C# codebase)

Steps to Reproduce

1. Configure codex mcp-server as an MCP tool in Claude Code (.mcp.json)
2. Ask Claude Code to use the Codex tool to analyze the project
3. Codex MCP server starts but produces no response for several minutes
4. Eventually times out or must be manually stopped

Expected Behavior

The MCP server should:

• Respond within a reasonable time (< 30 seconds for initial analysis)
• Provide progress feedback if the operation takes longer
• Have a configurable timeout to prevent indefinite hangs

Actual Behavior

The MCP server hangs indefinitely with no output, no progress indication, and no error message. The Claude Code UI shows "Wandering..." status while waiting.

Additional Context

• The same project can be analyzed quickly by Claude Code's built-in tools
• The issue may be related to the MCP server attempting to read the entire project context before responding
• Lowering reasoning_effort does not seem to help significantly