'Description' in IDE

The App has a Description property in the IDE.
If I build a Mac app, this doesnt appear to be visible.
If I build a Windows app, and double click a document that is associated with the app, Windows offers to open it with the description rather than the App Name.

My question is twofold…
Why is Windows using the description, and/or
If I change the description to something specific to Windows (eg Blah for Windows), will that show up anywhere on a Mac build of the same code?