Amaunator's uncertainty instilled a strong sense of uncertainty in the target. This uncertainty prevented the victim from executing whatever action he or she intended to in a non-hostile situation while it merely delayed a person's readiness to enter combat in a combative situation.
The spell could take multiple targets and leaving the area in which they were affected did nothing to shake off the uncertainty. Only waiting until the spell expired helped.
Amaunator's uncertainty required verbal and material components, the latter being a fragment of a turtle shell.