Hi there, bbloodworth.
Thank you for posting your concern here in QuickBooks Community.
The downloaded data in QuickBooks Desktop depends on what your bank shares with us and how they're posted online. However, the features and fields from the banking page in QBDT default and there's no option to extend the "Downloaded As" description field.
Since the said option is not ready in the QuickBooks Dekstop version, I encourage you to submit feedback to our Product Development Team for review when determining features to be added in updates. This can be done directly through your account by clicking the Help icon in the top right corner and select Send Feedback Online. QuickBooks Desktop is constantly changing and evolving based largely on the suggestions and requests of users.

I suggest visiting our QuickBooks Firm of the Future blog to know about the latest news and updates from QuickBooks Online. From there, you'll also see the newest announcements about the product.
Feel free to leave a comment below if you have any other questions about QuickBooks. I'm always around to help.