I had two questions about how a note could be attached to something and not show up in the room description. Here is a simple solution:
The Foyer is a room.
The window is in the foyer. The description is “Upon closer examination, there is a small note written on the window.”
The note is scenery and part of the window. The description is “The note reads: Save the cheerleader, save the world.”
If you do not want the window to show up either, do this (just make sure to mention it in the room description):
The Foyer is a room. “This small room is illuminated by light coming through a lone window.”
The window is scenery in the foyer. The description is “Upon closer examination, there is a small note written on the window.”
The note is scenery and part of the window. The description is “The note reads: Save the cheerleader, save the world.”