Condition is the product
Two of the same reference are not the same object. Write the condition in a way a stranger can check: case unpolished or polished, scratches and where, crystal replaced or original, bracelet stretch. Vague words like excellent mean nothing after the parcel arrives.
Photograph the case flanks and the clasp. Those are the two places wear shows and the two places a buyer will look first when it lands.
Say what is in the box
Box, papers, spare links, service receipts. List them as a line each rather than writing full set, because full set means different things to different people, and the disagreement always happens after payment.
Service history belongs on the page
If it was serviced, say by whom and when. If it was not, say that too. A watch with an honest gap in its history sells; a watch with a story that falls apart under a question does not, and enthusiasts ask good questions.
Shipping a watch is its own paragraph
Say how it ships, insured or not, and to where. A buyer spending real money wants to read that you have thought about the parcel. One line about insurance and tracking does more for the sale than another photo of the dial.
Let the conversation do the closing
Watch sales rarely complete on the first tap. Someone opens the page, reads, and asks one thing. Because the shop is inside the chat, that question arrives beside the listing rather than in a different app, and you answer it once instead of assembling context from three places.