A predicate can be narrowed through annexation (iḍāfah) or qualification by an adjective. Such wording identifies which relation or kind of description the speaker intends.
«زيد أخوك»
Zayd is your brother.
«زيد أخوك الكريم»
Zayd is your generous brother.
The second variant adds an explicit quality to an identified relationship. Whether that addition is rhetorically useful depends on what the listener needs to distinguish.
More wording is not necessarily better. Qualification is valuable when it helps recognition, removes ambiguity, or supplies the relevant aspect of an assertion.