Anyone else observing a massive gap in LLM capabilities within Cursor? For example, ChatGPT 5.2 is 1000x better when used in chatgpt.com than when used inside Cursor. It’s gotten so bad that I am now copying and pasting things from Cursor GPT5.2 into ChatGPT 5.2 to fix all the problems the Cursor LLM is causing. I see this on Anthropic LLMs too. Why are the LLMs so lobotomized within Cursor? I feel like I am going backwards to the old copy-and-paste vibecoding route, these CLI agents are NOT performing anywhere close to what they should be. If I ask ChatGPT 5.2 to do something I get results that are so much better than what the same supposed LLM inside Cursor produces

I recommend MAX mode. Without it the 250 line limit can severely affect the output – you’ll notice the same issue with copilot

[image] RawToast: Without it the 250 line limit can severely affect the output Agent in Cursor can write over a thousand lines at a time. What limit are you talking about?

what about Ask modes and Plan modes? Because at this point, I am getting much better results using GPT 5.2 in ChatGPT.com to build plans rather than calling the same LLM in plan mode

I hate to corroborate the experience of the OP, however, there does appear to be something about Cursor, that seems to make the models…..well, dumber, than their “raw” counterparts. I had to use Claude Code alongside Cursor recently, because I was updated to 2.4.x, and it was a disaster. First the terminals had sever issues, then once I hit 2.4.21, the agent itself was completely and utterly hosed, non-responsive, and the only solution ended up being downgrading all the way to 2.3.34. I switched to using Claude Code at first, then was using the two side by side after the 2.3.34 regression (there were still some quirky issues for a while). There DOES seem to be something about Cursor, that makes the models behave worse than they do natively. They do extra things, not asked for, step out of bounds despite rules, or are just plain dumb (i.e. just now, cursor wrote a bunch of extra code I did not ask for, and added a number of unnecessary data object mapper functions, that literally recreated the exact same data structure…just less some properties here or there….but, its TypeScript, which is structurally typed!) Claude Code does not seem to have the same…”mental disabilities”…at least, I have not encountered the same problems. Claude Code doesn’t crap .md “documentation” files all over my codebases. Claude Code doesn’t usurp my control and commit arbitrarily, just because I had it commit once (Cursor now does this CONSTANTLY, and I cannot seem to reign it in, despite rules, explicit instructions in the same chat NEVER to commit arbitrarily on its own without explicit authorization from me each time, etc.) I would encourage you guys not to dismiss this notion that Cursor performs worse than the raw models out of hand…because, I think it does. If necessary, I think this could be empirically demonstrated as well. Sadly, this seems to have become worse in more recent weeks or the last month and a half? There was a period of time in the fall last year, that Cursor was performing really well, models were blazing fast, and they seemed very savvy and smart. However more recently, that has all faded, and THE DUMB seems to be taking over. Its rather disappointing, but, the recent stark differences in my experience with Claude Code vs. Cursor, really hit home and make me really, truly wonder why Cursor seems to…fraught with quirkiness and problems.

in theory the main difference is the system prompt that Cursor AI adds. Same goes for Claude Code It is possible Cursor AI team keeps meddling with system prompts. There may be a lot of junk that confuses the model

That is my suspicion as well, but I have little to back it up, its just a suspicion. I have a fair amount of rules, however I recently (just a couple days ago) went through and marked most of them as “Apply Manually”, reducing the baseline rule load to about 6-9. It varies depending on some “Apply Intelligently” rules and some that are glob based. I used to have over 20. I also spent some time to optimize the rules themselves, eliminating unnecessary replication of instructions, excessive examples, etc. to reduce the amount of context they consume. I had hoped that would help things. Sadly, this did not seem to improve the nature of the Cursor agent…it still seems to just be quirky, and continues to do annoying things like crap .md files all over the place (despite having a rule stating never to do that, and also despite explicit in-prompt instructions not to! One of the most baffling issues!) It also does seem like past chats, have an influence on future agent behavior. I used to do some things in the past that I no longer do, and the agent, again despite rules, kept doign those things, until I went through and deleted all the old chats that had anything to do with those behaviors I no longer want the agent to engage in. I don’t know how that integrates, but, it seems to…maybe its a section of the system prompt, I don’t know. In any case, I wonder if I should just go through, and remove the majority of my historical chats… Sad thing is, the agent engages in bad behavior, then its part of that history, and I wonder if somehow that might be part of the problem? In other words: PRECEDENT?

Here is an exemplar case right here. This used to work PERFECTLY! My rule is VERY clear about how the agent should run httpie. Despite the rule being apply intelligently with all the necessary description details to have it apply whenever the agent tests, I still explicitly reference it as well because Cursor seems highly inconsistent with its rule application for any rules not “Always Apply”. The rule, as you can see, is EXPLICIT about using –session-read-only, however the agent just ignored that, and used –session anyway. This always results in httpie trying to update the session config, which breaks it, breaking all subsequent testing attempts. Drives me crazy. So the rule is very clear, the agent MUST use –session-read-only. Agent just decided not to actually apply that part of the rule, I guess? Why is it so quirky!?!? This used to work PERFECTLY. I never even had to reference the rule, it applied, and the agent used –session-read-only religiously. But not any more… [Screenshot 2026-01-27 at 2.55.02 PM] Why?

It’s input not output. The file_read tool is limited to 250 lines per call. Some models may call it multiple times to get more input So if you give it a 600 line file, it may only read 250 lines; although, it could make another call for 500, or two for all 600. Max can read up to 750 in one tool call, so will always be fine. This is the same issue CoPilot has, but at least Cursor has Max mode to get around the issue. You’ll see even Opus Copilot will return garbage at times, yet via Opencode or Claude Code it will handle the task fine. I find this most obvious when asking it to document an old system, as this will involve lots of reading of files > 250 lines long This probably is true for rules if you still use them (and skills too)

[image] RawToast: The file_read tool is limited to 250 lines per call Gemini 3 Flash: [2026-01-28_11-48-39] [image] RawToast: So if you give it a 600 line file, it may only read 250 lines; although, it could make another call for 500, or two for all 600. Max can read up to 750 in one tool call, so will always be fine. Are you on the old request-based system?

If they’ve changed this, they need to make it clear: [image] Does MAX mode provide additional benefits other than increasing the context window length? Discussions @JhonW00d There are not as many differences now between Max and non-Max modes as they used to be. One of the differences for Max mode is how many lines are read at once from a file. Max mode reads 750 lines and non-Max 250 lines. Cursor uses AI models from several providers. Each AI model has a context limit set by the AI provider. We also may set a context limit to a model depending on its performance in non-Max mode. Max mode is not smarter for any model. More info about our models. … @condor

Cursor LLMs Lobotomized?

Discussions

RawToast (RawToast) January 28, 2026, 1:56pm 13

If they’ve changed this, they need to make it clear:

@condor

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Cursor LLMs Lobotomized?

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