aria-describedby

Tooltips — auch wenn sie bereits zugänglich sind — sollten für die optimale Nutzung in Screenreadern mit zwei ARIA-Attributen ergänzt werden.

The aria-describedby attribute is used to indicate the IDs of the elements that describe the object. It is used to establish a relationship between widgets or groups and text that described them. This is very similar to aria-labelledby: a label describes the essence of an object, while a description provides more information that the user might need.