What are some best practices for writing prompts when using Amazon Bedrock's language models to get good results?

To get reliable results from Amazon Bedrock’s language models, focus on writing clear, specific prompts with sufficient context and iterate based on outputs. Start by defining the task explicitly. For example, instead of asking, “Explain cloud computing,” specify the audience and depth: “Explain cloud computing to a junior developer in three paragraphs, focusing on scalability and cost benefits.” This reduces ambiguity and guides the model toward your goal. Include formatting requirements if needed, like “Return the answer as a JSON object with keys ‘summary’ and 'key_features’” to ensure structured output for APIs or downstream tools.

Providing context is critical. If you’re generating code, state the programming language, libraries, and use case. For instance, “Write a Python function using pandas to filter a CSV file for rows where ‘status’ is 'active’. Include error handling for missing files.” This narrows the scope and improves relevance. You can also include examples in the prompt. If generating product descriptions, provide a sample input-output pair to align the model’s tone and structure (e.g., “Input: Wireless headphones with 20-hour battery. Output: These wireless headphones…”). For complex tasks, break them into steps: “First, summarize the user’s query. Then, suggest three solutions.”

Test and refine prompts iteratively. Start simple, then add constraints based on initial outputs. For example, if a prompt like “Write a blog intro about DevOps” produces generic results, revise it to “Write a technical blog intro about DevOps best practices for CI/CD pipelines. Avoid marketing jargon and focus on automation tools.” Adjust parameters like temperature to control creativity versus consistency. If the model ignores specific instructions, rephrase or add emphasis: “IMPORTANT: Do not include personal opinions.” Log problematic outputs to identify patterns (e.g., the model often omits error handling) and update prompts accordingly. This trial-and-error approach helps tailor prompts to your specific use case.