HTML Guide for aria-describedby
An a element with both an href attribute and aria-disabled="true" is invalid; either remove aria-disabled or the href attribute.
The aria-disabled attribute is used for interactive elements to indicate that the element is perceivable as disabled by assistive technologies. However, using aria-disabled="true" in combination with an href attribute on an a element is not valid, because the link remains actionable for both user agents and assistive devices. Instead, if a link should appear disabled, you should remove the href attribute, use CSS for styling, and optionally use aria-disabled="true". If you need the element to always act as a link, avoid aria-disabled and control user access through application logic.
Incorrect:
<a href="page.html" aria-disabled="true">Visit Page</a>
Correct—Option 1: Remove aria-disabled, keep link active
<a href="page.html">Visit Page</a>
Correct—Option 2: Remove href, use aria-disabled, for non-actionable item
<a aria-disabled="true" tabindex="-1" style="pointer-events: none; color: gray;">Visit Page</a>
In the second correct example, setting tabindex="-1" prevents keyboard navigation, and pointer-events: none; makes the link unclickable, while aria-disabled="true" makes the disabled state accessible.
The aria-describedby attribute is used to indicate the IDs of the elements that describe the object. It should reference an existing ID on the same document, but that id was not found.