I mean the main reason they do that is they have to take it seriously. If they decided to ignore anonymous tips, then how many actual situations would they fail to prevent and handle.
Swatting is just taking advantage of the fact that they have no choice but to take it seriously.
That being said, if it’s a place that gets swatted regularly or a place that’s likely to be swatted due to various reasons they should have precautions in place with people they can trust in order to double check before acting, or at least be prepared to go in with their guns still holstered.