MCP tools not loaded as deferred tools when using mcp-remote proxy

Bug Report

MCP tools are not appearing as deferred tools in Claude Code, despite the MCP server being correctly configured and responding to tool discovery.

Environment

• Claude Code: v2.1.42
• OS: macOS (Darwin 25.2.0)
• mcp-remote: installed globally via npm at /opt/homebrew/bin/mcp-remote

Configuration

~/.claude/mcp.json:

{
  "mcpServers": {
    "zotero": {
      "command": "mcp-remote",
      "args": ["https://mcp.johanlindholm.com/zotero", "--transport", "http-only"]
    }
  }
}

Steps to Reproduce

1. Install mcp-remote globally (npm install -g mcp-remote)
2. Configure ~/.claude/mcp.json as above (pointing to a StreamableHTTP MCP server)
3. Start Claude Code

Expected Behavior

The 20 tools exposed by the MCP server should appear as deferred tools, discoverable via ToolSearch.

Actual Behavior

No deferred tools from the zotero MCP server are loaded. ToolSearch returns no results.

Verification

Running mcp-remote manually confirms the server is reachable and responds correctly — tools/list returns all 20 tools. The issue appears to be in Claude Code's MCP initialization/discovery, not the proxy or server.