fix and improve arguments' description
fix and improve arguments' description

Signed-off-by: bruceauyeung <5ee6267ac32775d3759645233b22b193189cd28d@zte.com.cn>

luxas/heapster,burmanm/heapster,adfin/statster,huangyuqi/heapster,piosz/heapster,luxas/heapster,bruceauyeung/heapster,johanneswuerbach/heapster,bluebreezecf/heapster,AlmogBaku/heapster,burmanm/heapster,bruceauyeung/heapster,AlmogBaku/heapster,bluebreezecf/heapster,huangyuqi/heapster,Stackdriver/heapster,piosz/heapster,johanneswuerbach/heapster,adfin/statster,whuwxl/heapster,krzyzacy/heapster,Stackdriver/heapster,whuwxl/heapster,krzyzacy/heapster