Tooltips are helpful for providing your learners with additional information and prompts, they’re also very handy for providing your learner with additional references.
To add a Tooltip
Find an area of text that you would like to add your tooltip.
Double click the text to open the text editor:

Select the text you’d like to add the tooltip to:

Press the link button:

Press ‘Insert Tooltip’:

Enter the text that you would like to be displayed:

…and press ‘Insert’.
Now when you hover over your text your tooltip will display.