Comments/descriptions are generated in SQL script.
(Comments (e.g. Oracle db), Descriptions (MS SQL Server db).)
In the DDL Script Generation dialog | Detail Settings tab, the checkbox ‘Create Comments’ or ‘Create Descriptions’ must be selected.
Important information on MS SQL Server db - Besides the condition above, the following stands for this database (let me quote the Help file):
To generate the table, column descriptions for SQL Server db in Toad Data Modeler, schema/owner has to be defined.
Please see the Entity Properties form | General tab and from the Schema box select a schema or click the icon on the right to open the Schema dialog and define a new schema, then select it for the entity.
Please let me know if it works fine for you. Thanks.