I think I messed up the evaluate question in English language?

So I did my English language paper 1 yesterday and our question was " the writer attempts to create an atmosphere of mystery, evaluate how successfully this is achieved"

For my introduction I said the writer has successfully used the setting, themes and events to create mystery. Then I wrote points and about how exactly these things create mystery for the reader. Although I think my analysis was quite perceptive, I don't think I used evaluative words. Would that be a problem and would it cap my mark or would it be okay if I just explained how mystery was created?