Keep it simple.
You only need your website link, a short explanation of what the business does, the main action you want a potential customer to take and what you currently observe.
You can describe symptoms rather than causes: slow pages, weak enquiries, confusing information, forms that may not work, irrelevant traffic, missing data or leads that do not move forward.
You do not need to diagnose the real cause yourself. Identifying the relevant technical, SEO, functional, analytics or customer-journey layers is part of the written diagnostic process.