When something is sauceless, it means it does not have any sauce on it.
Being sauceless is neutral, it just means there is no sauce on something.
Examples:
I prefer my pasta sauceless.
The pizza was sauceless and dry.
She likes her salad sauceless.
The burger was so sauceless, it was like eating cardboard.
The sauceless wings were so plain and boring.
He ordered a sauceless sandwich, but it was still tasty.