The only description i have been given in system update is a couple of what they call version numbers! And there's no other description except to say the update is a security patch for the 6.0 software. And thats what the last one said, when i recieved 48 new apps.
I think google is trying to overload my storage with all kinds of junk because they no longer want to support the older software!
I think your update should be from the manufacture of your phone, Samsung, or your carrier, other than google. And some suppliers of system update are used to giving more details description to their consumers while the others are not.
Maybe you will have to google and have a study for any new system update before accepting it.