The pleadings in the justice's court shall be:

(1) The complaint of the plaintiff, which shall state in a plain and direct manner the facts constituting the cause of action.

(2) The answer of the defendant, which may contain a denial of the complaint, or any part thereof; and also a statement, in a plain and direct manner, of any facts constituting a defense.

(3) When the answer sets up a setoff, by way of defense, the reply of the plaintiff.