Which is a best practice for prompt design in Agents?

• A. Be vague about tool usage to keep flexibility.
• B. Avoid stating safety rules to not constrain behavior.
• C. Provide minimal guidance on reasoning style.
• D. Be explicit about tool usage, safety rules, reasoning style, and clear success criteria.

Answer: (D)

Clear and reliable prompts guide an agent by setting explicit expectations for how it should operate. When you specify tool usage, the agent knows exactly when to call external tools, which tools it can access, and how to format their outputs. This prevents missed tool calls or inappropriate tool use, and it makes the agent’s behavior predictable.

Stating safety rules upfront keeps outputs aligned with allowed content and constraints, reducing the risk of harmful or inappropriate results and making enforcement and auditing much easier.

Clarifying the reasoning style helps the agent approach tasks in a consistent way—whether it should lay out steps, reason privately, or provide concise conclusions—so its process is easier to understand and evaluate.

Providing clear success criteria defines what “done” looks like, which removes ambiguity and guides the agent to complete the objective in a verifiable way.

Together, these elements create a well-defined prompt contract that leads to more reliable, controllable, and safe agent behavior.