LIST WITHOUT ID link(file.path) + choice(desc, " - " + desc, "")
FROM [[#]]
SORT file.name ASC
To address the issue of missing properties in your Dataview query, you can use the defaultlink function or a choicelink to handle cases where the desc property is not defined.
With default would look like this:
LIST WITHOUT ID link(file.path) + " - " + default(desc, "")
FROM [[#]]
SORT file.name ASC
But not sure if you can hide " - "
I am currently not behind my computer, so not able to test it