The wu shi pai is the rare piece of jewellery whose value rests on subtraction. A carved jade pendant can draw attention away from the material; an uncarved one cannot, because there is nowhere to hide a flaw. For that reason a good wu shi pai is often more expensive than a carved piece of the same weight.
The form is associated with a wish for a quiet, untroubled life — the phrase itself, 无事, means literally "no matter" or "no trouble." It is a sentiment rather than a claim, and we describe it as such.
Expect faint internal lines, and in the thinner plaque a slight variation in colour from one edge to the other. Those are properties of natural nephrite, not defects.