This summary is not the rule. The rule text controls.
Parties in a lawsuit can agree in writing to change some of the standard rules for gathering evidence before trial, without needing to ask the judge first. This is called a stipulation.
For example, both sides can agree to take a deposition (sworn testimony given outside of court) at a different time, place, or with a different amount of notice than the rules normally require. They can also agree on who conducts the deposition. As long as both sides agree in writing, the deposition can still be used in court just like any other deposition.
The same idea applies to other types of discovery, like requests for documents or written questions. The parties can agree to change how these processes work to fit their needs.
There are limits, though. If the judge has already made an order that says something different, or if a past court order conflicts with the agreement, the parties cannot just ignore it. In those cases, the court's order comes first, and the parties would need to get the judge's approval to make changes.