You can do that for yourself. Look at your gig description, the things you do like schema markup and yoast design.
I searched “yoast design” and found one other seller.
I also searched “yoast template” and got this:
We Didn’t Find Any Results For Your Search.
Everytime you only find one or few sellers, or no seller, it’s an opportunity for a “monopoly” situation, meaning you could monopolize the market.
My recommendation is have a mixed of tags, “google index” gives you 99 results when you search.
Wordpress optimization gives you 2017 results.
So if Fiverr allows you to use 5 keywords, I would use a mix between popular and rare keywords.