This summary is not the rule. The rule text controls.
When someone is accused of a misdemeanor and a formal complaint is filed, the magistrate doesn't always have to issue an arrest warrant. If the magistrate believes the accused person will show up to court on their own, they can issue a summons instead. A summons is basically an official notice telling the person when and where to appear in court.
This gives magistrates some flexibility. Not everyone accused of a minor crime needs to be arrested right away. If the magistrate trusts that the person will cooperate and come to court voluntarily, a summons is a less harsh way to get the case moving.
However, this doesn't mean a warrant is off the table forever. If the person doesn't show up after getting a summons, or if circumstances change, the magistrate can still issue an arrest warrant later. So getting a summons instead of being arrested isn't a guarantee that an arrest won't happen down the road.