A better example of how I think this could actually be helpful is if I were to send the blender.file to someone else to work on. If they could go to the object outliner and find notes or descriptions on objects (again, backups, variations etc), it would save a bit of head scratching on their end.
Cheers!
That is not directly possible in Blender.
What some people do, is to simply make a Text File (with the Text Editor, for instance) with notes (and Save the .blend, with the Text Editor open). This always looks really efficient and useful to me, both for yourself, as for others, if you share the .blend file. This can also be helpful in pointing out differences between Incremental Saves, for instance.
There is an addon, but it hasn't been updated in a few years so some of it's features may not work, but the ability to add notes to objects and scenes still works. It's called noter. The original is here https://github.com/rovh/Noter
It was updated for 3.3 here: https://www.gs614.ca/Noter/