Updating a file

I’m just wondering is there a general rule about updating music files? Are we encouraged to update our tracks with what we feel would be better mixes and how many times would be considered too much?
Also is the only thing that has to be reviewed the files? Can you just change tags and the rest by yourself?

…and to add, when you make a change to a track do you have to be very specific about what you did, like ‘I lowered the snare by 1db and the bass by 2db’ , or do you just give a more general report?