The details should be coming out of a recordset correct?
Add the eCart Set Session Value server Behavior, Insert -> WebAssist -> eCart -> General -> Set Session Value. set the trigger to Recordset is not empty. for the value, click the lightning bolt and select the Description column from the recordset.
After the Set Session Value code is added to the page, you may need to move the code to make sure it is after the recordset code.