Hi, thank you for visiting the forum and sharing your question. In my opinion, there actually is a correct answer to your question. I think one would know whether or not a spell (or any other energy work, like healing, etc.) is correct or not if it does or does not accomplish that which the spell caster (or energy worker) intended it to accomplish.
But I want to be sure I understand your question. When you say you’re concerned about a spell being correct, do you mean appropriateness, or technique? In other words, are you concerned about it being the appropriate spell for the appropriate situation? Or are you concerned with the correctness of its nuts and bolts, i.e. its wording, structure, materials used, etc.? Please clarify. Thanks.