Hi Camila,
The ESP discovery tool is only able to get the schema of one table at a time. The PowerDesigner product is designed more with the intention of managing and reverse engineering database schemas.
I have seen other users write SQL stored procedures that query a given database's system tables and write out the "CREATE SCHEMA" CCL language. I have a set of stored procedures that were created to read the Sybase IQ system tables and generate CCL. I have been given permission to send this to you if you are interested, just let me know.
Others have used various database's DDL schema export tools (like DDLGEN.EXE for Sybase ASE) to export the "CREATE TABLE" SQL to a file and then used an editor's global search and replace to alter the syntax and the columns to match the available data types in ESP.
Thanks,
Neal