The default description extracted for invoices on AutoEntry is the supplier account name. You can change this in two ways:
If you only need to change it once, you can do so from within the blue 'eye' icon to the left of each invoice to view it.
Once the invoice is opened you can edit the description in the box highlighted below. This will only save for this individual invoice.
If you would like to change the description on all invoices by a specific supplier this can be done from within 'Company Contacts'.
From the list please click on the Supplier name. You will then be brought to a screen as shown below and can change the 'Default Description' for all invoices by this supplier in the section highlighted by the red box. Once you have added your description, click 'Save Changes' at the bottom of the page.