It’s not necessarily that the Description property doesn’t sync. But, it could be somewhat “hidden”.
When an Events table is synced with GCal, only few fields containing some of the properties of the events are directly added to the table. But the data should be there and you should be able to find it.
To do so, before displaying your Upcoming Events table as Cards, you can hover an event sitting in the field Event with your mouse and in the modal, you should be able to find the Description property you’re looking for .
There should be an Add Column button next to the description which should do what you’re asking