Users come first. That should be your number one rule whether you use Etsy, Artfire, or a self-hosted webstore. What this means is that while you should be using important keywords in your titles and descriptions, those are useless if your customers are turned off by the way your titles and descriptions are written or how your photos look they aren't going to buy no matter how well you rank in search.

This concept is called "conversions", you want the highest conversion rate you can get (for a web store that the % of visitors who make a purchase). If you have 5000 visitors a month with a conversion rate of 1% you are doing the same amount of business as a shop with 1000 visitors but a 5% conversion rate (50 sales per month). If you have 10,000 visitors a month but no one buys anything you might as well have had no visitors at all.

Here are three fictional titles for the same fictional product:
"Marvin the Robot"
"Soap robot lavender scented blue soy moisturizing handmade vegan"
"Marvin the Robot soap, moisturizing lavender scented soy soap"

The first is terrible, it doesn't even tell you what the item is. You can have creative names for your product, a memorable name may stick in a visitors head better than something descriptive but generic. However if the not having many clues, or misleading clues, about what the item is will hurt you as well. If visitors are clicking on "Marvin the Robot" expecting a toy or artwork not soap then that's not going to help your sales.

The second is better but a visitor is going to see it as either boring at best and spammy at worst. Why? because it's just a list of attributes of the product. People react to language in certain ways and if words don't read like a meaningful statement people aren't going to perceive it as valuable. Try reading your titles out loud and see how they sound.

The third title strikes the right balance. It both is descriptive, telling you a lot about the product (that it is a robot shaped soap, made of soy, moisturizes the skin, and is lavender scented) while also giving you product personality. If you don't know about the importance of telling a story about your business please go read All Marketers are Liars by Seth Godin he describes the concept far better than I can but the gist of it is that people respond far more to being told a good authentic story than they do just being given the bare facts.

I used titles in this example because Etsy's new CEO just released an update on improvements to relevancy search and how to make titles better for search. I applaud the Etsy team for making much needed improvements to the search engine but I think it gave people the wrong idea. Ranking higher in search will not do any good if your customers aren't enticed by what they see.