In my experience, it pays to have a conversation with the DM out of game time to tell them that they should probably describe whatever there is to see in the room.
If there’s no time pressure and no traps, there’s no reason you can’t just say “I rummage through every shelf in NPCs personal library in search of the book!” or something.
Because when you’ve got like 4 hours a week of free time to prepare for the game, grabbing something 5e compatible and ad-libbing parts you didn’t feel like preparing ahead of time is easier than learning a whole new system.