Howto do column descriptions in CDS for sap:label in XSODATA?

I want to use CDS and XSODATA (with annotation: enable OData4SAP) and get sap:label annotations in the OData $metadata document (cf eg XS/ODATA access to analytic view field lables | SCN).

Where can I define the label text in the CDS document? Can I have these texts multiple languages?