MCP Tools Not Available to AI Despite Server Running

Bug Report: MCP Tools Not Available to AI Despite Server Running

Product: Claude Desktop (macOS)
Version: Latest (February 2026)

Description

Remote MCP server connects successfully and shows as "running" in Claude Desktop, but the AI cannot access or use the registered tools.

Steps to Reproduce

1. Configure a remote MCP server in claude_desktop_config.json:

{
  "mcpServers": {
    "gmail": {
      "command": "npx",
      "args": [
        "mcp-remote",
        "https://example-server.railway.app/mcp",
        "--header",
        "Authorization: Bearer <token>"
      ]
    }
  }
}

1. Restart Claude Desktop
2. Server shows as "running" (green indicator)
3. Server logs confirm tools are loaded (e.g. gmail_read_emails, gmail_send_email, gmail_search)
4. Ask Claude to use any tool from the MCP server
5. Result: Claude responds "I don't have access to Gmail" (or similar)

Expected Behavior

Claude should recognize and use the registered MCP tools when the server is running.

Actual Behavior

Claude claims it has no access to the tools, despite:

• Server showing "running" status
• Logs confirming successful tool registration
• No errors in server logs

Troubleshooting Attempted

• Renamed server in config
• Cleared MCP caches
• Updated mcp-remote to latest version
• Tried both SSE and streamable-http transport
• Complete Claude Desktop reset
• Disabled Chrome extension (chromeExtensionEnabled: false)

Environment

• macOS Darwin 25.2.0
• Transport: streamable-http via mcp-remote
• Server: FastMCP hosted on Railway

Additional Context

The server works correctly when accessed directly via Python/CLI. The issue appears to be Claude Desktop not passing the available tools to the AI context.

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Submitted via Claude Code