This summary is not the rule. The rule text controls.
If someone gets called as a witness and refuses to be sworn in or refuses to answer questions, the court can hold them in contempt. This applies to the court where the case is actually being heard, not just any court.
In practice, this means a witness can't simply ignore a subpoena or clam up on the stand without facing consequences. If a person is properly called to testify and won't cooperate, whether by refusing to take the oath or refusing to answer questions, the judge has the power to punish that behavior as contempt of court. This could mean fines or other penalties, depending on what the judge decides.
The point of this rule is to make sure witnesses actually participate in the legal process once they're called. Courts rely on witnesses telling the truth and answering questions so cases can move forward fairly. Without some way to enforce this, people could dodge their responsibilities as witnesses with no consequences.
