The description should still be there in the Repository Settings (under Repository Details), however it's no longer displayed on your repository overview page.
Instead, Bitbucket encourages you to create a README.md file in the root of your repository which will be displayed on your repository overview page. Markdown is much more customizable than just plain text, but plain text is fine if you just want to copy your existing description over. The easiest way is via the online editor, which you'll get if you click the "Create a README" button on the repository overview page.
Hello! My name is Mark Askew and I am a Premier Support Engineer for products Bitbucket Server/Data Center, Fisheye & Crucible. Today, I want to bring the discussion that Jennifer, Matt, and ...
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs