This is counter-intuitive and it is the single most profitable thing in this post: describing the flaw makes the item sell for more.
The arithmetic
A bidder looking at an item with an unexplained shadow, a vague "good condition", or a photograph that carefully avoids one side does not assume the best. They assume something between the best and the worst, and they bid accordingly.
That gap is a discount, and you are paying it on every item where the condition is unclear.
Name the chip and the gap closes. The bidder is no longer pricing in an unknown — they are pricing in a chip, which is a smaller number.
How to word it
Be specific and unemotional. "A 4mm chip on the foot rim, not visible when it is sitting on a table." Not "slight damage".
Say where, how big, and whether it shows in use. Those are the three things a buyer wants and the three they will ask about anyway.
Show it. A photograph of the flaw is worth more than a paragraph about it, and live, you can turn it over and point.
What this prevents
Most disputes here come down to the same thing: a difference between what a buyer thought they were getting and what arrived. A named flaw cannot become that dispute.
Questions people ask
Will I put buyers off?
Some. They are the ones who would have opened a dispute.
What counts as a flaw worth mentioning?
Anything you would want to know if you were buying it. If you are debating whether to mention it, mention it.
What if I did not notice it until after it sold?
Tell the buyer before you send it. A message beforehand is a conversation; a surprise in a box is a complaint.
Does this apply to new items too?
Yes — a factory second, a damaged box, a missing accessory.
Next: photographing an item.