1.
If you say that a comment is double-edged , you mean that it has two meanings, so that you are not sure whether the person who said it is being critical or is giving praise.
Even his praise is double-edged.
ADJ
2.
If you say that something is double-edged , you mean that its positive effects are balanced by its negative effects, or that its negative effects are greater.
But tourism is double-edged, boosting the economy but damaging the environment...
a double-edged sword: see sword
ADJ : usu v-link ADJ