These are big cases that affect many workers at once, those in which an employer retaliated or challenged a subpena, and cases in legal areas that the agency wants to develop. I call them the Gonna Getcha Guidelines, or GGGs for short. Enforcement Guidance on Preemployment Disability Related Inquiries and Medical Examinations Under the Americans with Disabilities Act of 1990. During it you simply cannot ask questions,or do anything else, that might elicit information about a disability. Your documents and procedures are good enough when they'll prove to an EEOC investigator, and if necessary to a jury, that you did it right.
Job descriptions are key documents.
Bear in mind that under the ADA, you must draw them up before you make any effort to fill a position. Human resources managers dearly love their tests. You get hit with an employee discrimination complaint to the EEOC or the State Human Rights Division. You are upset. You want to fire this person.