Good wording answers practical questions
Warmth gets a smile; clarity gets a reply. A guest should be able to work out the occasion, the host, when it starts and roughly ends, where it is, what it will cost them and when you need an answer - without sending you a follow-up question.
The three gaps that most often stall a reply are duration, cost and who else is coming. If your wording leaves any of those open, add a line.
If you would rather start from an example
Our guide to inviting people online has six complete invitations you can copy - casual drinks, dinner at home, a milestone birthday, a children’s party, a ticketed outing and a last-minute plan - each with the cost, duration and reply-by already built in.