MCP tool calls rendered as raw <mcp> text tags instead of executing in terminal

Support Bug Reports
1

When using Cursor Agent (Composer/Chat) to perform tasks, the AI is outputting raw JSON/XML tags (e.g., <mcp>{...}</mcp>) directly into the chat interface instead of actually executing the commands. This results in a “pseudo-call” loop where the AI thinks it has sent a command, but nothing happens on the system.

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug
The Cursor Agent (Composer/Chat) fails to execute MCP tool commands and instead renders the raw internal communication tags (e.g., <mcp>{"command": "..."}</mcp>) as plain text in the chat interface. This creates a “pseudo-call” loop where the AI believes it has performed an action (like git pull or npx), but the command is never actually sent to the terminal or the MCP server.

Steps to Reproduce
Trigger a task that requires the MCP server or terminal to execute (for example, “Deploy to netflix” or “Synchronize with GitHub”). After that, the AI can execute them at the beginning of a session, but then it will output the original tag instead of executing them

Expected Behavior
The AI should recognize the tool-call syntax and execute the command in the background/terminal, showing a “Running command…” UI element instead of displaying raw JSON/XML tags to the user.

Screenshots / Screen Recordings

image
image876×1054 104 KB

Operating System

MacOS

Version Information

Version: 2.3.39
VSCode Version: 1.105.1
Commit: 6b09e84affa31c144fca27f2f4de0c229d69a140
Date: 2026-01-16T00:14:22.110Z
Electron: 37.7.0
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Darwin arm64 24.1.0

For AI issues: which model did you use?
Sonnet 4, Gemini 3 Flash and GPT-5.2 codex high

For AI issues: add Request ID with privacy disabled
a92c2e11-57b8-4bde-9eb9-4c41e31c4acf

Does this stop you from using Cursor?

No - Cursor works, but with this issue

2

Hi there!

We detected that this may be a bug report, so we’ve moved your post to the Bug Reports category.

To help us investigate and fix this faster, could you edit your original post to include the details from the template below?

Bug Report Template - Click to expand

Where does the bug appear (feature/product)?

  • Cursor IDE
  • Cursor CLI
  • Background Agent (GitHub, Slack, Web, Linear)
  • BugBot
  • Somewhere else…

Describe the Bug
A clear and concise description of what the bug is.

Steps to Reproduce
How can you reproduce this bug? We have a much better chance at fixing issues if we can reproduce them!

  1. …
  2. …
  3. …

Expected Behavior
What is meant to happen here that isn’t working correctly?

Screenshots / Screen Recordings
If applicable, attach images or videos (.jpg, .png, .gif, .mp4, .mov)

Operating System

  • Windows 10/11
  • MacOS
  • Linux

Version Information

  • For Cursor IDE: Menu → About Cursor → Copy
  • For Cursor CLI: Run agent about in your terminal
IDE:
Version: 2.xx.x
VSCode Version: 1.105.1
Commit: ......

CLI:
CLI Version 2026.01.17-d239e66

For AI issues: which model did you use?
Model name (e.g., Sonnet 4, Tab…)

For AI issues: add Request ID with privacy disabled
Request ID: f9a7046a-279b-47e5-ab48-6e8dc12daba1
For Background Agent issues, also post the ID: bc-…

Additional Information
Add any other context about the problem here.

Does this stop you from using Cursor?

  • Yes - Cursor is unusable
  • Sometimes - I can sometimes use Cursor
  • No - Cursor works, but with this issue

The more details you provide, the easier it is for us to reproduce and fix the issue. Thanks!

4

Hey, thanks for the detailed report. That’s unusual behavior, especially the part where commands work at first and then start showing up as raw tags.

To dig in, I’ll need a bit more info:

  1. MCP config: can you share the contents of .cursor/mcp.json (mask any API keys if needed)?

  2. Which MCP servers you’re using: the screenshot shows git, but I’m curious which servers are connected

  3. Developer Console logs: open Developer Tools (Help > Toggle Developer Tools), reproduce the issue, and look for errors. Logs mentioning “mcp” or “tool” are especially useful

  4. Repro steps: does this happen every time after N requests in the chat, or only with specific commands?

As a first step, please update to version 2.4.x and check if you can still reproduce it there.

5

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