How to change a card title and description?
To make changes to a particular card, open the Card Details by clicking on a card. A popover window will appear for editing the selected card. After editing a card title, the change will be saved automatically.
If the card does not have a description click on Add description and type your text. Click on the Save Changes button to save the description.
To edit card description just click on the existing one and change the text. Then click on the Save Changes button to save the new description.