AppleScript automatically formats your script when it’s compiled to make it easier to read.
If you set styles or fonts in the body of a script, they will be reset when the script is compiled.
Font and styles are used by AppleScript to help identify each type of item, such as reserved words, commands, or variables.
Dialogs called by a script use standard system fonts and styles, so these can’t be changed using the text formats in Script Editor.
Fonts and styles used in the Description pane will not be overwritten during a compile.