Any information in square brackets is considered optional and will be ignored by PLEX.
This is a good article to read on the recommended naming convention (it’s the TV show page but there is also one for movies).
Support Articles | Plex Support is also a good place to look if you have questions/issues prior to coming to the forum because it might answer your questions.
I’m just a bit afraid what happens to description fields in case you have to do the Plex Dance so I thought about adding additional informations to the file name (similar like you mentioned it).
“Search function friendly” and easier to detect if you have to move directories to another HDD (or similar).