The fit criterion, not the description, is the real requirement. The description you write is the stakeholder’s way of stating the intention of the requirement. If your stakeholders are like most of us, they speak using everyday language, which is, unfortunately, often ambiguous and often not precise enough. You need to clarify the requirement with a fit criterion that is stated in unambiguous, precise terms and probably uses numbers or a measurement to convey its meaning.
Link · 12. Fit Criteria and Rationale