Can get MCP tools working in Cursor anymore

[sgandon (SeB)]

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

I am setting up MCP tools (that used to work). Those MCP tools are showing green and displaying the tool sets properly in the UI.
But when I use the plan or agent mode and ask for available tools those added tools are not known to the LLM.

Steps to Reproduce

Enable MCP tools in the Cursor settings (I enabled Serena that used to work fine) and see them green (23 tools enabled).
Use the Agent mode, use Sonnet 4.5 (it seems that Ask mode was not using all tools) and ask this prompt.
“What are the available tools”

and you’ll get something like this

I have access to a comprehensive set of tools to help you with coding tasks. Here's what I can do:
File Operations
Read files - View contents of any file in your workspace (including images)
Write files - Create new files or overwrite existing ones
Edit files - Make precise string replacements in existing files
Delete files - Remove files when needed
List directories - Browse folder contents and structure
Search & Navigation
Search code - Fast text/regex search across your codebase (using ripgrep)
Find files - Locate files by name patterns using glob matching
View linter errors - Check for syntax and style issues
Code Editing
Edit notebooks - Special support for Jupyter notebooks (.ipynb files)
Make targeted edits - Precise code modifications with context awareness
Terminal & Commands
Run shell commands - Execute any terminal command, install packages, run scripts, git operations, etc.
Monitor running processes - Track long-running commands and dev servers
Project Management
Task tracking - Create and manage TODO lists for complex multi-step tasks
Mode switching - Switch to Plan mode for architectural discussions
External Resources
Web search - Look up current information, documentation, or recent updates
I can read, write, search, execute commands, and help you build or modify your projects. What would you like to work on?

Expected Behavior

expecting to have Serena tools listed.

Of course I have tried with many other MCP tools and none of then appear to be exposed to the LLM.

Operating System

MacOS

Current Cursor Version (Menu → About Cursor → Copy)

Version: 2.2.36
VSCode Version: 1.105.1
Commit: 55c9bc11e99cedd1fb93fbb7996abf779c583150
Date: 2025-12-18T06:25:21.733Z
Electron: 37.7.0
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Darwin arm64 25.2.0

For AI issues: which model did you use?

Sonnet 4.5

For AI issues: add Request ID with privacy disabled

dd233d2f-6212-4b79-baa9-53b644079a0a

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

[Steve_Wright]

I too have this problem primarily with the Atlassian MCP. It works randomly, more often failing than succeeding. At this point its not practical to use, which is hugely disappointing as I really want this to be a part of my workflow.

Version: 2.2.36
VSCode Version: 1.105.1
Commit: 55c9bc11e99cedd1fb93fbb7996abf779c583150
Date: 2025-12-18T06:25:21.733Z
Electron: 37.7.0
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Linux x64 6.8.0-87-generic

    "Atlassian": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://mcp.atlassian.com/v1/sse"
      ]
    },

[deanrie]

Hey, thanks for the report. This is a known issue - MCP tools show green status in the UI but are not accessible to the agent.

The team is working on a fix. Similar cases: MCP servers are not accessible in Cursor Desktop chat despite no visible errors with connection and Agent has trouble detecting available MCP tools

For diagnosing your case, could you provide:
2. @Steve_Wright - can you share the Request ID from the problematic chat? (Chat context menu > Copy Request ID)
3. MCP server logs from the Output panel (View > Output > select your MCP server from the dropdown)

This will help engineers match your cases with the logs.

[Steve_Wright]

Here is the conversation ID for a failed attempt to add Jira issues to an Epic. a0a801f1-7d4e-4a84-bef1-ffe15291a056

2025-12-18 15:32:22.735 [info] Handling GetInstructions action
2025-12-18 15:32:35.477 [info] Handling CallTool action for tool 'getJiraIssue'
2025-12-18 15:32:35.478 [info] Calling tool 'getJiraIssue' with toolCallId: tool_7afd7d8e-0e13-4d2b-aa70-82b358eb75b
2025-12-18 15:32:35.478 [error] [3989795] [Local→Remote] tools/call

2025-12-18 15:32:35.478 [error] [3989795] [Local→Remote] tools/call

2025-12-18 15:33:07.621 [info] Handling GetInstructions action

[Chris_Drake]

Here’s some related posts about MCP bugs that your team needs to investigate as well:-

Windows mcp.json major bug with non-stdio servers

Where does the bug appear (feature/product)? Cursor IDE Describe the Bug Cursor establishes N duplicate connections to every mcp server listed in mcp.json where “N” is the number of servers in that file. e.g. if you have 5 servers, cursor establishes 5 connections to each on of those 5 servers - 25 in total! This bug has been around for ages - PLEASE FIX IT. Steps to Reproduce add 2 more more non-stdio mcp servers Expected Behavior 1 connection per server only. Operating System Windows 10/…

Stop Shipping Unstable Builds

I’ve been using Cursor since the 0.x versions. In the past, I was genuinely excited about every new release — I would literally click Check for Updates almost every day. Lately, however, I feel the opposite: I hesitate whenever I see a new version available. The reason is simple: almost every update breaks something. If it’s not one issue, it’s another. Version 1.7 felt relatively solid and stable. But from 2.0 onwards, things have gone downhill — and there are already many posts out there abo…

No matter how many times we report this, it never gets fixed.

[sgandon (SeB)]

the latest update (Version: 2.2.43) seems to have fixed the issue.
Let’ wait to have other peoples feedback and see if holds in time