This idiom is used to mean that one has exhausted one's skills.
In ancient times there were no donkeys in Guizhou Province. Somebody brought a donkey from somewhere and tied it to a tree at the foot of a mountain. A tiger saw the donkey, and thought that it must be a fearsome monster. It hid behind a tree and spied on the donkey .When the donkey brayed ,the tiger was frightened, thinking that the donkey was about to devour it. After a while ,seeing that the donkey had not moved, the tiger approached it and teased it. The donkey became angry, and kicked the tiger. The tiger thought to itself:"Is that all it is capable of?" It then jumped on the donkey and ate it.