alt.hn

2/18/2026 at 10:55:53 PM

Ask HN: In Cursor/agents, do plugins hide MCP tools from the main agent?

by azebazenestor

2/19/2026 at 5:53:31 PM

I built a stdio-based MCP multiplexer (mcp-hub) that connects to multiple backend MCP servers and exposes them as a single server. From the host agent's perspective, all tools are flattened into one namespace with server-name prefixes — telegram__send_message, linkedin__get_profile, etc. The agent doesn't know or care which backend handles each tool.

To answer the question directly: it depends on the implementation. In Cursor's case, MCP servers are registered individually and the agent sees all tools at the same level. A multiplexer like mine acts as an abstraction boundary — the agent sees one MCP connection, but tools from N backends are available through it. The tradeoff is namespace management vs. connection simplicity. With 10+ MCP servers, a single gateway is significantly easier to configure and debug.

by hifathom

2/19/2026 at 4:35:56 PM

From what I have seen, plugins usually act as an abstraction layer — the main agent interacts with the plugin, not each underlying MCP tool directly. It keeps things cleaner and easier to manage, especially when multiple tools are involved.

by allinonetools_

2/19/2026 at 12:06:27 AM

I've recently started using Codex and installed Figma MCP. The outputs were really good. I achieved a 90% success rate, and I fixed the rest myself.

by beratbozkurt0