While every chart has a default title & a tooltip, it is possible for each user to modify them.
Follow the steps below to modify the description of a chart.
1. Click the 3 dots at the top right corner of the chart and click Edit element.
2. Go to the Description tab
3. Enable Element Title and/ or Element Tooltip and enter the desired text in the fields below the buttons.
4. Click Apply to save the changes.
The title & the tooltip have now changed as below.