When something is vague, ambiguous or obscure there is confusion and uncertainty. For people to know how and when to act, there must be clear communication that the listeners comprehend (1 Cor 14:7-11,19). Otherwise, ask questions to reveal the truth and remove all doubt or possible misunderstanding.
The prophet was instructed, “Write down the revelation and make it plain…” (Hab 2:2). Paul said, “We do not write anything you cannot understand…” (2 Cor 1:13,14). When we share the gospel it should be clear and explicit.