Microsoft Office tools have a built-in accessibility checker. Under the Review tab is a Check Accessibility button. 
Selecting the button checks the document for accessibility errors and considerations displaying suggestions about how to rectify or resolve the concerns. Consider checking every document for accessibility before publication.
Example of suggestions from the Accessibility Checker
Most educators do not have a background in designing and creating educational materials with accessibility in mind. An accessibility checker will catch design mistakes and guide educators through a process of how to fix them. Consistent use of an accessibility checker consistently helps people learn how to design the next material with less errors. Educators will learn from their mistakes and begin to anticipate what is needed to mitigate errors. The following video explains how to use Grackle Docs to check files created using Google Suite for accessibility errors.