The brusque explanation by the store clerk left me wishing I hadn't asked the%0D%0Aquestion of him. I decided to no longer shop there after that experience.%0D%0A%0D%0AWhy is the word brusque used instead of brief?%0D%0Ato illustrate that the employee was difficult to understand%0D%0Ato show that the store clerk was extremely busy%0D%0Ato highlight that the explanation was not simply short, but also rude

The word "brusque" is used instead of "brief" to highlight that the explanation was not simply short, but also rude. The store clerk's manner was harsh and curt, giving the impression that they were uninterested or annoyed by the customer's question.