@Andrew yes although it's not shown in the interface all edits are stored and available via the API and card history.
This post describes the (somewhat roundabout) way of viewing description changes:
https://help.trello.com/article/783-recovering-the-description-of-a-card-that-has-been-changed
If you wanted an easier to view solution then it could be automated via the API. This is something you could use Trellinator for:
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