It uses as example the calendar synchronization script.
For setting up an icon, two things are needed:
Its contents may be as follows:
[Desktop Entry] Encoding=UTF-8 Version=0.1 Type=Application Name=Synchronize Calendar Exec=osso-xterm /usr/local/bin/syncCalendar Icon=sync X-Osso-Type=application/x-executable
Putting osso-xterm before the name of the script ensures that a terminal is launched so that you can see its output. This is not needed for scripts that open their own window.