It really isn’t difficult to make your gig description unique. It’s just like writing anything else of quality. For example, I have written at least a dozen separate articles about crate training puppies, but each one is entirely unique with fresh content. Gig descriptions may not be poems, but they can be excellent sales pitches and clear descriptions of what you offer.
When you write your gig description you use your own style, modifiers that describe your own services, etc. It may have some elements in common with other gig descriptions selling similar products, but it should still be basically original. In particular, copying/pasting from someone else is against the Terms of Service.
If it is too difficult to write a gig description that is unique, there are plenty of great copywriters on Fiverr who can do it for you. You just want to choose one that has a ton of Fiverr experience. (Note - I am not a copywriter and am not advertising my services.)