When you created the attribute did you check the Attribute Storefront Property of attribute . You need to enable attributes " Visible on Catalogue Pages on Storefront " property . After enabling clear the cache and re-index all the indexers .
This will make your required attribute to show on front-end .
Other than this I am sharing you my personal experience of using Amazon Integration other than M2epro . I've had same problem while product listing and Cedcommerce's Amazon Integration has a proper solution for this .
Like what happen is Amazon allows Description:
-- 1-2000 chars (including spaces and line breaks)
-- Html tags are not allowed.
It is very normal that magento description field may contain characters more than 2000 and can contain html tags.
So, Cedcommerce's Amazon Integration provides it in two ways:
1. Auto remove all html tags and unnecessary spaces, then strip the description to 2000 chars and upload the Magento description to Amazon.
2. Choose a different field than Magento Description (still validations are done) .
It helped me listing my products on Amazon with my kind of description . You could check their plugin here -
Amazon Integration