Who needs to use it?
Describe the people the site should help. Their level of knowledge, likely questions and decision process affect the structure more than a list of favourite colours.
What should they understand?
Write a plain-English description of your offer. Identify the information people need before they can decide whether to contact you, book or buy.
What should happen next?
Choose the main action for each important page. Explain where an enquiry goes, which booking tool actually exists and who is responsible for responding.
What do you already have?
Bring the original brand assets, useful existing content and access to the current website. Mark which materials are approved, which are experiments and which need replacing.
What will you need to edit?
List routine changes: service text, images, projects, articles or FAQs. Agree an editing workflow rather than assuming that ownership of source code makes every change easy.
What defines a finished project?
Agree page coverage, key interactions, content responsibilities and launch checks. Include actual enquiry delivery, useful handover information and a rollback approach. A complete brief sets boundaries without prescribing every design decision.