What does the Habitable Zone (HZ) concept primarily act as when searching for exoplanets?

Answer

A filter for candidates that meet the basic prerequisite of potential liquid water

The HZ is not a guarantee of habitability but rather a necessary first step filter based on energy input, indicating which worlds might meet the prerequisite of having liquid water.

What does the Habitable Zone (HZ) concept primarily act as when searching for exoplanets?
astronomyplanetssolar systemhabitable zonegoldilocks zone