Here is the short summary of the poem :
-It was noon time of a hot day when the poet goes to his water trough to fill his water pitcher.
-As he goes there he sees that a golden-brown snake is drinking the water from his tap
-He feel a great pleasure to have the snake as his guest and consider himself as a host
- He decides to wait for his turn to come as the snake was the first comer
-He observes that the snake was long with slackness soft body.
- The snake drinks the water as the cattle do
- The poet knows that the golden snake was venomous and must be killed but his heart tells him not to do so
- His voice of education tells him to kill the snake but he doesn 't do so
-Then the snake turns back to go to his dark burrow
- The poet doesn 't like it and suddenly he throws a log of wood at him
- He didn 't want the snake go back but irionically he forces him to do so
- after he do so he regrets a lot.
- He feels the same as the ancient mariner who killed the innocent albatross
- He wishes that he might get a second chance to improve his mistake
- He repent alot for the underworld king- the snake.
That 's all
Hope it helps..