Hello @ForrestBarker,
My suggestions it to edit the description field after sharing the geographies to ArcGIS.
1. Enable this option when sharing.
2. Click this to open the shared map
3. Click the geography layer here to open it.
4. Click the Data tab
5. You might see the field is locked for editing
6. Click on the fields button > click on the description field > Allow editing and save
7. Double click on the description field value and you should be able edit it.
I hope this helps,
Fasil T.