In my experience, it's not just about the details in terms of notes to the designer but about having a relativlely detailed chronicling of what happened at the rehearsal. What was accomplished vs. what the goals were for that day? How were the actors that day? Was therae a particular scene or a beat that was giving them trouble, etc? One production I worked on, I found that these details really helped my director keep track of areas to focus on for the next rehearsal. Also, he was gone on a cruise for a week so these detailed really helped keep him apprised of the progress being made.
One thing I learned from a stage manager mentor, in terms of designer notes, particularly props and scenic notes, is that she would phrase the note from the perspective of the item itself (if that makes sense). Instead of saying "we want/need the table to be 2 ft. wider" she would word it "the table wants to be 2 ft. wider." Basically she was personifying the item in question. I find it helps so that your reports aren't too "We want/need this, We want/need that," etc.