You can change the description of a database with toolkit as follows:
Start toolkit on your database:
\> toolkit dbname
Select 6 - Database Menu from the Toolkit Development Menu.
Select D3 - Modify Database Description from the Database Menu.
Enter the new description and press STORE <F5>, or press CANCEL<F1>-X to leave the old description unchanged.
You can change the description of a database with a command as follows:
c:\> dbadmin -vu -C "new comment" dbname
You should enclose your new comment in quotes.