Tool update_memory not found (still happening)

[MiguelT]

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Cursor IDE Describe the Bug This bug has come up a lot. Cursor becomes detached from its memories and starts going off-script which results in a lot of wasted prompts. Trying to get Cursor to access memories during these times results in “tool update_memory not found"

Sometimes it depends on the agent, other times not. It definitely happens with Composer 1, less so with Claude Sonnet. This bug has been reported a lot but is always either ignored completely or “we’ll look into it” and ignored. One could assume that the bug isn’t being fixed because it’s not in Cursor’s best interests to fix something that results in wasted prompts. Does Cursor actually intend on looking into this bug at some point?

Is cursor purposely not fixing "tool update_memory not found" bugs because it results in wasting more prompts?

I’m not going to post a bug for this because there are plenty that I’ll link below. The issue is that Cursor regularly loses context of its rules / memories and goes off script, resulting in wasting lots of prompts. Attempts to add or address these memory issues results in Cursor returning with “tool update_memory not found”. Sometimes switching agents works, and sometimes it doesn’t. One direct side effect of this bug is that users waste more prompts trying to get Cursor to do what it should a…

Steps to Reproduce

In Composer 1, try to add a new rule or memory, especially after or during Plan mode

Expected Behavior

Should be adding a rule / memory and shouldn’t be disconnected from the update_memory tool

Operating System

MacOS

Current Cursor Version (Menu → About Cursor → Copy)

Version: 2.0.77 (Universal)
VSCode Version: 1.99.3
Commit: ba90f2f88e4911312761abab9492c42442117cf0
Date: 2025-11-13T23:10:43.113Z
Electron: 37.7.0
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Darwin arm64 25.1.0

For AI issues: which model did you use?

Composer 1, Sonnet 4

Does this stop you from using Cursor

No - Cursor works, but with this issue

[sanjeed5 (Sanjeed)]

Thanks for the report. Can you please check if you’re still facing this issue on the latest version?
You can get the latest version from Download · Cursor

[MiguelT]

No change whatsoever, cursor still detaches from all rules and memories which directly results in users wasting prompts. This one was in Sonnet 4.5 but it’s happening in all of them randomly.

update - looks like now it just entirely deleted all rules. This really doesn’t feel like it’s happening in good faith.

[MiguelT]

Still happening, also the new thing is when I tell it to update .cursorrules (which I didn’t used to need but cursor keeps randomly deleting its internal user-added rules), it freezes and refuses to show an Approve button for the file change. Every single time.