AI Assistant - Do instructions actually work?

I am trying to give the AI some simple instructions, something like this:

"Don't write any explanations, except I ask specifically for it. Also don't write any comments in the code."

I tried to add this in the settings. I tried both General - Chat Instructions and Built-In Actions - Commit Message Generation.

Unfortunately, the AI doesn't behave any different. It still explains everything in detail and writes comments into the code. I thought its maybe the AI is to young. But now since the internet is hyping GPT-5, I wonder why its still not working - at all.

You guys have any suggestions, or should I hope for GPT-6?

Thanks :)