esaProbeScheduleGroupDescr is a read-create DisplayString (1 to 256 characters) describing the purpose of a probe schedule group. An administrator fills this in so that other operators looking at the schedule group table can understand what the group is for without having to infer it from the probe list alone. For example, a description like 'nightly maintenance window – core ring probes' immediately tells a colleague why a batch of probes stops testing every night without them having to ask.