Tool Tip

A good tooltip briefly describes unlabeled controls or provides a bit of additional information about labeled controls, when this is useful. It can also help customers navigate the UI by offering additional—not redundant—information about control labels, icons, and links. A tooltip should always add valuable information; use it sparingly.

There are two components you can use to display a tooltip:

Tooltip: A styled tooltip that you can display on a chosen target.
TooltipHost: A wrapper that automatically shows a tooltip when the wrapped element is hovered or focused.

Best Practices

Content

Don’t use a tooltip to restate a button name that’s already shown in the UI.
When a control or UI element is unlabeled, use a simple, descriptive noun phrase. For example: “Highlighting pen”. Only capitalize the first word (unless a subsequent word is a proper noun), and don’t use a period.
For a disabled control that could use an explanation, provide a brief description of the state in which the control will be enabled. For example: “This feature is available for line charts.”

For a UI label that needs some explanation:

Briefly describe what you can do with the UI element.
Use the imperative verb form. For example, "Find text in this file" (not "Finds text in this file").

For a truncated label or a label that’s likely to truncate in some languages: (*Truncated label - one that has been shortened)

Provide the untruncated label in the tooltip.
Don't provide a tooltip if the untruncated info is provided elsewhere on the page or flow.
Optional: On another line, provide a clarifying description, but only if needed.