Where can I find the variable names to use for AppleScript?

For instance, I know AppleScript can be used to resize the application switcher by
using "set {appPaletteWidth, appPaletteHeight} to its size". I found this from someone else's script for something. My question is, where can I find the other manipulable variable names (appPaletteWidth, appPaletteHeight) for the application switcher? In particular I'd like to change its opacity, but if someone can just point me to the place in the documentation where I can find, would be greatly appreciated.

In the AppleScript:

set {appPaletteWidth, appPaletteHeight} to its size

The variable names appPaletteWidth and appPaletteHeight are entirely at your choice. You could call them fred and bill if you wanted.

set {fred, bill} to its size

All that statement really is is a way to set two variables that you choose to the width and height of the size. The only special name is size.

To find out the special names like size you use the dictionary (in Script Editor, use the Library window, and add the application), or by using the properties property which returns all the properties as a dictionary. For example:

tell application "Keyboard Maestro Engine"
	tell window 1
	end tell
end tell


{closeable:false, zoomed:true, class:window, index:-1, visible:true, name:"Applications", miniaturizable:false, id:32741, miniaturized:false, resizable:false, bounds:{0, 25, 46, 759}, zoomable:false}