An author might choose precise words over vague words because the author could want the reader to visualize the writing. The reader could be confused and visualize something else entirely if the author uses vague words. A good example is if the writer is writing instructions, hel she would need to be very specific. Another example is if the writer is composing a poem, it would be best if he/she uses precise words of what they're describing. Ex., Vague: The flower is pretty. Precise: The pink tulip bloomed beautifully.
The meaning of "vague" is uncertain or not precise words. The author might do so because he or she wants the reader to visualize some certain image. With clearer words, the reader can better visualize. With imprecise words, the reader could visual something completely different. Or build up suspense and tone.
Vague: The cemetery was spooky and looks old.
Precise Fog surrounded the whole cemetery, and spiderwebs stuck on the gravestones. Chills shivered up my back.
With more precise words, the reader can get a better feeling of the setting or image the author is trying to get across.
