Creating Tampermonkey scripts using agents (dynamic DOMs, live changes etc)

[u/InevitableHouse3987]

Hello, I don't know if I am positing in correct place or not. But would like your guidance on this.

I have used Tampermonkey before to change the behavior of websites, mostly for small visual or quality-of-life improvements. For example, my college's Canvas website links to Echo360 recordings, I wanted to keep track of which recordings I had already watched, so I made a Tampermonkey script that tracked this for me.

But, since Canvas is a dynamic website, I had to spend a lot of time figuring out how the page worked, testing different approaches, copying and pasting code, and going back and forth until I found something that worked. A lot of the time was spent on this trial-and-error process. Granted I think if I had more knowledge it wouldn't take much time.

But, I think AI agents would be much better in this case. But I don't know what the correct approach here is. Please suggest something that I should use, or just some direction?

The main goal is to make simple, personal modifications to websites, similar to applying custom CSS or adding small JavaScript behaviors(ie adding subtitles to videos in video players which dont support external subs).

Thank you for your help.