Explicit Criteria over Vague Instructions

When Claude underperforms on a task, architects often reach for a vague fix like be more precise or try harder. This rarely works.

The reliable move is to replace vague instructions with explicit criteria: a concrete rule that says exactly when to act.

Compare these two code-review prompts:

• Vague: "Be more precise about comments."
• Explicit: "Flag a comment only when it contradicts the code it describes."

The second one gives the model a testable boundary it can apply consistently.

"Be more precise" assumes Claude already knows what you mean by precise. It doesn't. It will guess, and different runs will guess differently.

Vague instructions push the decision boundary into the model's interpretation, where it is probabilistic and inconsistent.

Explicit criteria pull that boundary back into your specification, where it is stable across runs. This is the same instinct that makes hooks (deterministic) safer than prompt guidance (~90% probabilistic) for critical rules — be as concrete as the stakes demand.