All fields under Field Proprties are allowed to have options->comment added, that is saved in DDL via Doctrine's [options: comment="..."] mapping. While it would be nice if the "Description" also populated comment in the DDL, this isn't the biggest problem.
With a Many-to-One association added in the Associations tab a new field, say "pt_id", will be added in Field Properties tab. However, adding text in options => comment does not populate [options: comment="..."] in #[JoinColumn] but only for #[Column].