Okay, so what writer/text is it? If you have an extract could you send it? You're only focusing on 'description', so stuff like language devices really: metaphors, similes, personification, [in poems especially, anaphora, enjambment, caesura, etc.], hyperboles, irony/satire? Loads of stuff to look for. Then basically describe how those examples (use quotes obviously) is relevant to the whole text, or the writer, or context etc. Maybe there's an underlying theme, maybe they're trying to give a message/moral. Is there a lot of descriptive writing in terms of setting or characterisation, or not? Depends on what you're writing about.