This summary is not the rule. The rule text controls.
Both sides in a lawsuit can agree, in writing, to change some of the normal rules about gathering evidence before trial. This is called discovery, and it includes things like depositions, where someone answers questions under oath.
Normally, depositions have to follow specific rules about who can run them, when they happen, where they happen, and how much notice people get. This rule lets both sides skip those requirements if they agree to it in writing. For example, they could agree to hold a deposition somewhere unusual, or let someone other than the usual officer handle it, or give shorter notice than normally required.
The same idea applies to other types of discovery too, like written questions or requests for documents. If both sides agree in writing, they can change how those procedures normally work.
This rule gives people more flexibility and can save time and money, since they don't have to ask the court for permission every time they want to handle discovery a little differently. However, a judge can still step in and stop these agreements if there's a good reason to. This rule applies the same way in district court as it does in other courts.