Consider adding from which spell list and what ability is being used as your spellcasting attribute. If it is intended to be from any class and treated as a (your current spellcasting class)spell for you then its a much bigger benefit than it would be if it was or an untyped cantrip (such as racials). (eldrich blast being cast as a wizard spell with intelligence as a spellcasting modifier comes to mind). The new cantrip not counting against your cantrips known for that class would be a necessary detail added if that is the case. If the new cantrip is limited to one already on your spell list or untyped (such as a racial cantrip). you may want to add a skill or language proficiency to bring it closer in power to similar feats in UA and Xanathar's Guide.