The poem is an ode addressed to the West Wind, personifying it as a powerful force of nature. In 3 sentences, the summary is:
The poet describes the West Wind's action over the land, sky, and water, portraying its ability to destroy dying leaves and carry seeds while also preserving new life. He asks the wind to carry his "dead thoughts" and spread inspiration among mankind, believing this will usher in a new spring and rebirth. Finally, the poet pleads for the wind to make him its instrument so that through him it can spread prophecy and change upon the earth.