• Title: what it is and its strongest fact — “Recipe blog, 40k monthly visitors, 6 years old”.
• Description: how it makes money, where visitors come from, how much time it takes, what a new owner could improve. Use headings and lists — the editor has buttons for them.
• About the sale: why you are selling, what is included, how you hand it over and how long you help afterwards.
• Proof: say which proof you can show (analytics access, payout screenshots, a call).

Never put contact details or outside links in the listing — buyers contact you through the marketplace, which keeps both of you safe.