TL;DR: for standard HTML controls and standard ARIA patterns (widgets), you do not need to add instructions for screen readers on how to use them nor what they are. When a screen reader encounters an element on the page that invites interaction beyond reading, it typically provides users with instructions…| Adrian Roselli
Accessibility of web content requires semantic information about widgets, structures, and behaviors, in order to allow assistive technologies to convey appropriate information to persons with disabilities. This specification provides an ontology of roles, states, and properties that define accessible user interface elements and can be used to improve the accessibility and interoperability of web content and applications. These semantics are designed to allow an author to properly convey user ...| www.w3.org