All documents need to be checked for accessibility before posting. Microsoft Office programs and Adobe Acrobat have built in accessibility checkers that can help you fix any outstanding issues.
If you can avoid using documents in webpages, FAQs, etc., it's best to do that. Attaching a document requires the user to have software to access it, it slows down access to information, and it requires you to assess accessibility outside of your web environment. Any global fixes to accessibility or design on your web platform won't impact content pulled in from outside of your web environment like PDFs, Word docs, etc.
Use different titles for each presentation slide
Fillable documents (forms) are labeled appropriately
Use built-in accessibility checkers in various software tools (e.g., Microsoft Office, Adobe Acrobat)