We use the pdf comment tool, I guess IT got some pro version of Adobe. The basic reader doesn’t have it. I hate the thing (get off my lawn!) but you get used to it. It was so much easier to hand mark stuff. But then you have to print a hard copy, mark up, rescan in and that was worse, especially remotely when I had to email my document to my home machine then email back to myself on the office machine, before we got the integrated VPN that can print directly from the office machine to my desk at home.
You have to figure out how to draw the circle or arrows, how to change their color and thickness and so on, it’s a learning curve, still a PITA compared to manually hand marking but I guess that’s what we have to do now. Technology making our lives “easier”.