This is a category of sets, editions and licensed releases, and almost every question a buyer has is about which one you have.
Name the release
Publisher and imprint, as printed. Language. Edition — standard, deluxe, omnibus, collector's. Print run or printing, if the book says.
Show the spine and the copyright or publication page. That page answers more questions than any description, and it takes five seconds on camera.
Volumes and completeness
For a set, say exactly which volumes are present and which are not. "Volumes 1 to 12 of 15, missing 7" is a sellable, honest listing. "Near complete set" is not information.
If volumes are in different conditions, say which ones are worse.
On licensed and unlicensed releases
Unofficial printings exist in this category, and a buyer may ask. The useful answer is where you bought it and what the book itself carries — publisher, imprint, barcode and the publication page, shown on camera.
What nobody can do is settle the question over a video call. If you cannot say where a book came from, say so and price it as unverified. "Bought second-hand, I cannot confirm the edition beyond what is printed inside" is an honest sentence that sells.
Selling an unofficial printing as an official one is a different matter: the counterfeits policy covers it.
Figures and merchandise
Box condition, completeness, whether it has been displayed and for how long, and sunlight. For boxed figures, the toys guide applies — the box is a large part of the value.
Delivery
Paper, damp and spines. Packing manga and figures.
More: how to sell on Metzee, pricing anime and manga.
Questions people ask
Do I need to know the printing?
No, but show the publication page and let the buyer read it.
Should I sell a set together or split it?
Together usually brings more, and buyers completing a run will pay for the gaps. Say which you are offering.
Does a dust jacket matter?
On editions that came with one, yes. Say whether it is present.