Use tooltips to describe icons

Icons are not always easy to identify on their own. When you use components that don't have labels — for example, icon-only action buttons and tabs — make sure to use tooltips to provide context for the icons.

Don't use tooltips to communicate crucial information

Show crucial information at all times, not just when a tooltip is displayed. A tooltip should only be used to provide supplementary context or hints to the message shown in help text.

For example, in a scenario where a user is entering their password into a field, the crucial information would be to state the password requirements. Supplementary context would be a message about how to get help if they have forgotten their password.

Be concise

Tooltips should be as concise and clear as possible. Keep the text to 1 or 2 short sentences. If the information you need to communicate is longer than that, look into using a different design.

If a tooltip is written in a full sentence (or is 2 or more sentences), include a period at the end. If it's a short phrase or is only the name of a tool, action, or icon, don't add a period to the end.

Don't place actions inside a tooltip

Tooltips appear only on hover or when in keyboard focus. They should not contain actions or links.