Options C and E are correct because disciplined prompt iteration is an evidence-based improvement cycle. First, compare the output with the original task requirements and success criteria. Identify a specific weakness, such as missing evidence, excessive length, incorrect tone, poor structure, ambiguous instructions, or failure to follow a required schema. Then make a targeted change addressing that weakness and compare the new output with the previous version using the same evaluation criteria.
Option B changes nothing except the sampled response, so it does not reliably diagnose or repair the prompt. Option D is false because additional iterations can introduce regressions, conflicting instructions, or unnecessary complexity. Option A proposes an impossible and wasteful stopping rule; there are effectively unlimited alternative phrasings. Iteration should stop when the output meets the established quality threshold, when improvement has plateaued, or when a different model, workflow, tool, or human-editing approach is more appropriate.
Anthropic describes prompt engineering as a cycle of defining success criteria, testing representative cases, refining the prompt, and validating the result. Consequently, targeted modification and criteria-based comparison—not repetition or iteration volume—determine whether the process is productive. See Anthropic’s evaluation framework and prompting guidance .
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