Start with a decision, not decoration
A useful invitation brief names the reader, the decision or action the page should support, and the evidence required before design begins. For this project the audience is named guests who need both the tone of an occasion and precise attendance details. The working objective is to convey the occasion clearly and make the response process effortless. Write those two statements at the top of the brief and test every proposed section against them. Material that does not help the reader understand, trust or act should be removed, shortened or placed in a secondary channel.