MCP server listed as "Connected" in claude mcp list (CLI) but missing from session's connector list in Claude Desktop

Description

A custom HTTP MCP server is shown as Connected by claude mcp list, but it never shows up inside an active Claude Desktop session — the session behaves as if the server doesn't exist at all.

Steps to reproduce

1. Configure a custom HTTP MCP server (in this case named eclipse, pointing at http://127.0.0.1:8642/mcp).
2. Run claude mcp list — it shows:

``
eclipse: http://127.0.0.1:8642/mcp (HTTP) - ✔ Connected
``

1. Start/use a Claude Desktop session.
2. The eclipse server's tools are not available in the session — not in the loaded tools, not in the deferred-tools list surfaced to the model, and not listed by the session's own connector-status check (which does correctly list other configured servers, e.g. Playwright, Claude Docs, scheduled-tasks).

Expected behavior

A server reported as Connected by claude mcp list should be usable (or at least visible/listed) within the Claude Desktop session.

Actual behavior

The server is silently absent from the session entirely, with no error surfaced to the user.

Environment

• Claude Code version: 2.1.235
• OS: Windows 11 Pro 10.0.26200
• Rebooted the machine before starting the session — issue persists (rules out a stale/zombie process on the local MCP server).