Where does the bug appear (feature/product)?
Cursor IDE
Describe the Bug
It appears as though the MCP capabilities of cursor have been broken somewhere along the line. The models are unable to find any MCPs listed, when they executed the command LIST_MCP_TOOLS. Further, when explicitly instructed about how to use a specific MCP, it will not even try, it simply tries to list mcp tools, that command returns nothing, and no model is able to actually execute any MCP tools:
Current issue, as this is just the latest that has cropped up with regards to MCP tools, is the SupaBase MCP. I have it installed, and properly configured for my database, it shows up in my list of MCPs, and has a green dot indicating it is functional. However, as you can see here, the agent cannot find it. Nor can it even list any of the MCPs configured:
I suspect this may be the reason why the @Docs feature no longer works for Claude as well, as I think that was implemented as a built-in MCP. This has resulted in a severe handicap using Cursor now, as MCP tools have thus far been a fundamental part of my regular work with Cursor.
The recent releases with Cursor have caused severe regression and loss of critical functionality. I have even just completed a full and complete uninstall, scrub of ALL cursor related files, content, config, caches, etc. and reinstall from scratch. DESPITE that, Cursor still WILL NOT function correctly.
I rely on this tool that I pay $200/mo for, and week by week it has gone through a progressive degradation resulting in the LOSS of critical functionality such as MCP usage, terminals that simply cannot be executed, general instabilities and more. This has become extremely frustrating, as it is now hampering my ability to do my job at the pace demanded by my employers.
Steps to Reproduce
Install supabase mcp.
Issue a prompt that requests supabase list tables (or run a query, etc.)
Weep at lack of ability to use mcp.
Ask agent to list mcps.
Weep at no list of mcp servers despite them being configured.
Expected Behavior
Supabase MCP is not only LISTED when agent calls list_mcp_servers, but also usable by executing its commands.
Operating System
MacOS
Current Cursor Version (Menu → About Cursor → Copy)
Version: 1.6.45
VSCode Version: 1.99.3
Commit: 3ccce8f55d8cca49f6d28b491a844c699b8719a0
Date: 2025-09-22T18:22:38.013Z
Electron: 34.5.8
Chromium: 132.0.6834.210
Node.js: 20.19.1
V8: 13.2.152.41-electron.0
OS: Darwin arm64 24.5.0
For AI issues: which model did you use?
claude-4-sonnet (thinking)
claude-4-sonnet
grok-code-fast-1
grok-4-fast-reasoning
Does this stop you from using Cursor
Sometimes - I can sometimes use Cursor