Correct spelling, explanation: the word has its origins in the verb describe (which means to define, to characterize, to show in detail how big, small, etc. something is), and a suffix -ion that is used to create a noun from a verb. Replacing e in the word with i as in discription is incorrect.

Definition of description:
noun, explanation of what something is like, how it looks like, etc.
I know this was a terrible experience for you, but we are not able to find the thief without your description of him.

Idioms and phrases with description:
→ to be beyond description, above something that you can understand, much bigger or greater than you expected, usually surprising: Did you know he always passes part of his salary to the homeless? His kindness is beyond description.
→ of every description, of every category: Cars of every description took part in this rally.
→ beggar (all) description, nearly impossible or very difficult to explain: The way she prepared the home for the wedding is unbelievable – flowers, balloons… It really beggars all description.

Incorrect spelling, explanation: the word is a mix of verb describe (to illustrate, explain, give main characteristics) and suffix -ion, which main task is to create a noun from a verb or adjective. describe + ion=description. Any other form than description is mistaken.

Incorrect spelling

Incorrect spelling

Incorrect spelling