Heres a little format that I normally stay close to when listing:
[Title of listing, according to however you like to list]
[Intro (Today I/We are selling a brand new/slightly used XYZ)]
[Short history (My neighbor Greg Adams used this for about a year, forgot about it then I stole it out of his shed in the middle of a rainstorm, It was upgraded by me a few months ago, according to schematics found at https://hackxyz.net/dingomod.php
[last 3 digits of serial, preceded by omitted digits replaced by either asterisks, "*" or cross marks "x", "X")]
[official summary from manufacturer]
[link to whitepapers https://www.xyz.biz/xyz-ultra-rev-2/docs/specsheet.pdf
[trimmed specs from manufacturer]
[Fun facts and interesting tidbits]
I usually like to add these in as a little treat for souls depraved enough to make it to the bottom of these kinds of listings.
[plug yourself at the very bottom]
short description about what the account is about, what you usually can be found selling, how long youve been operating on the site, where you ship from and to, terms of sale, boilerplate stuff.
Thats about it, what you see above is my off-the-cuff format for most of my product listings. If any lainon has anything else to add, I welcome any and all thoughts on my example, what it did well, how it could be improved, or rearranged even.
Cheers OP, I hope we can all stand to learn something alongside everyone else in this thread.