I have come to a situation where I have moved the player to a room but I don't want a room description or even a room name to come on the screen unless you type "look". How can I do this?

thanks for reading this.

For the mystery room, do not enter text in the Description text block. Instead, go to the Advanced tab, click Edit Custom Player Commands and Add a LOOK command. In this custom command (which only works in this room) you can display a room description.