Where is the product description?

The Amazon Store module is a separate module which serves a different purpose. The setting you're referring to doesn't exist in this module.

I too am wondering how to access an Amazon Item's description using this module. Anyone have any suggestions? I thought this issue (#893316: Access specific fields from ASIN on node page using a view) might help, but it doesn't actually open up any additional item information.

I have the same problem.
There is no product description in the amazon.module AND in the amazon_store.module.

Just a note: Amazon does not provide one except for the US locale.

According to the Amazon API docs for Large Response Group, there is no LongSummary field (and I can't find a generic product description field there).

The Amazon Store module uses the EditorialReviews response group's first entry which is the Amazon product review. Is that not what you want?

If you visit your site's Amazon API Test page (at http://example.com/admin/settings/amazon/test) and enter an ASIN, do you see an [editorialreviews] response?

Example for ASIN B004M8NT5Y

Array
(
    [asin] => B004M8NT5Y
    [isbn] => 
    [salesrank] => 16
    [detailpageurl] => http://www.amazon.com/Jamba-Juice-Antioxidant-Booster-16-Ounce{snip}
    [listpriceamount] => 3200
    [listpricecurrencycode] => USD
    [listpriceformattedprice] => $32.00
    [lowestpriceamount] => 2500
    [lowestpricecurrencycode] => USD
    [lowestpriceformattedprice] => $25.00
    [amazonpriceamount] => 2500
    [amazonpricecurrencycode] => USD
    [amazonpriceformattedprice] => $25.00
    [binding] => Grocery
    [brand] => Jamba Juice
    [ean] => 0852056003012
    [label] => Jamba Juice
    [manufacturer] => Jamba Juice
    [numberofitems] => 2
    [packagequantity] => 2
    [productgroup] => Grocery
    [producttypename] => GROCERY
    [publicationdate] => 2011-02-03
    [publisher] => Jamba Juice
    [releasedate] => 2011-03-11
    [studio] => Jamba Juice
    [title] => Jamba Juice Acai Antioxidant Booster Shot, 16-Ounce Bottles (Pack of 2)
    [upc] => 852056003012
    [imagesets] => Array
        (
            [smallimage] => Array
                (
                    [url] => http://ecx.images-amazon.com/images/I/41bQz9aOZzL._SL75_.jpg
                    [height] => 75
                    [width] => 27
                )

            [mediumimage] => Array
                (
                    [url] => http://ecx.images-amazon.com/images/I/41bQz9aOZzL._SL160_.jpg
                    [height] => 160
                    [width] => 59
                )

            [largeimage] => Array
                (
                    [url] => http://ecx.images-amazon.com/images/I/41bQz9aOZzL.jpg
                    [height] => 500
                    [width] => 183
                )

        )

    [editorialreviews] => Array
        (
            [0] => Array
                (
                    [source] => Product Description
                    [content] => Nurture Your Feel Good Mission - A daily 1oz. Shot of Acai Antioxidant Booster gives you one big boost of 320mg Polyphenol Antioxidants to help you fight those pesky free radicals. One shot, once a day, and you’re ready to the seize the day.
                )

        )

    [customerreviews_iframe] => {snip}
)