In an earlier blog post, we provided potentially controversial advice to sellers to minimize investment in this area by keeping the description simple and concise.
eBay agrees: for display on mobile devices -- and ultimately to drive more conversion for mobile users -- eBay will "summarize" your description to 250 words:
"The new View Item description summary will improve conversion rates by providing buyers with a simple, user-friendly mobile experience so that they can make faster, better-informed purchase decisions. Now buyers can quickly read an item description summary or the complete description when it is 800 characters or less, without having to click through to the full description."
While you don't have to do anything right now, it sounds like eBay is going to enforce more stringent requirements on descriptions. We recommend you take a look at our article on eBay descriptions and simplify your descriptions as much as possible. Ultimately, it will help drive more sales.