ARIA: aria-description attribute

The global 
aria-description attribute defines a string value that describes or annotates the current element.
NOTE:
aria-description is still in W3C Editor's Draft for ARIA 1.3. For the time being, continue to use 
aria-describedby, which has been supported since ARIA 1.1.
Description
The global 
aria-description attribute provides a mechanism for the developer to describe or annotate the current element providing greater context for assistive technology users.
<div
  role="application"
  aria-label="calendar"
  aria-description="Game schedule for the Boston Red Sox 2021 Season">
  <h1>Red Sox 2021</h1>
  <div role="grid">…</div>
</div>
The 
aria-description attribute is similar to 
aria-label in that both provide a text string to associate with the element, but a label should be short and concise, while the description can be longer as it is intended to provide more context and information.
The 
aria-description and 
aria-describedby properties have the same purpose; both provide the user with additional descriptive text for the object on which it is set. If descriptive text is available in the DOM, use 
aria-describedby instead.
The 
aria-description property should only be used when providing a visible description is not the desired user experience. The 
aria-describedby attribute takes as its value a list of 
ids of the elements that contain descriptive text about the object. The 
aria-description is used when there is no appropriate descriptive text that can be associated with the object by 
id reference. If both attributes are present, 
aria-describedby takes precedence in defining the accessible description property.
The content of the description, whether set by 
aria-description or 
aria-describedby, should be flat text. If the content is very long, has semantic meaning requirements, or has a navigational structure, use 
aria-details instead.
Values
<string>
: The value is a string, an unconstrained value type, that is intended to be conveyed to the assistive technology user.
Associated interfaces
Element.ariaDescription
: The 
ariaDescription property, part of the Element interface, reflects the value of the 
aria-description attribute, which defines a string value that describes or annotates the current element.
Associated roles
Used in ALL roles.
Specifications
See also
HTML 
title attribute
aria-describedby
aria-details