You need to adjust your settings on the MonsterBooks desktop application before hitting the import button. QuickBooks requires that an item exists in your item list before you can add it to an invoice or receipt. If MonsterBooks cannot match the part number/manufacturer number in your CSV import up to an item in the item list in QuickBooks then it cannot add it properly nor put information about the item in the description field.
To remedy this make sure you all your items are mapped up to your products by either the part number or manufacturer number, depending on your choice between using the part number or the manufacturer number. If your products do not exist in QuickBooks at all then you either need to add them manually or use the "Add New Products" option in MonsterBooks which tells MonsterBooks to add any products that it cannot find a match for in the item list. For this to work properly you need to assign COGS, Asset, and Income accounts in the specified drop down boxes in MonsterBooks. All inventory parts in QuickBooks require that these three accounts are defined and the selected accounts will be used to populate these fields in the new items created by this method.