Would it be possible to request to add a line in the activity list (left hand side on desktop app) when description is changed besides having version history / or in conjunction with version history.

I agree with this suggestion. To avoid conflicts, it's better to have a version history feature to know who changed who and when it's changed.

This request looks to be a nice solution to avoid unintentional edits:

It will be nice to have this feature. Currently it is very easy to loose description text, I loose by accident today. With a history will be easier to get changes back. Btw, history can work for all fields like in Redmine.