A prompt has been revised eleven times over two weeks. Each revision added a sentence, and the current version contradicts itself in two places and restates one instruction three ways. Output quality has declined since revision four. You can spend one working session on it. What is the best use of that session?

Hardprompt-engineeringfundamentalsdiagnosisiteration

Last reviewed 10 Aug 2026

Remove the contradictions and the redundancy, then test against revision four as a baselineCorrect answer
Add a closing instruction telling the model which of the conflicting rules takes priority
Discard the prompt and write a fresh one from the original requirements
Roll back to revision four, since quality was last acceptable there

Show answer & explanation

Correct answer: A. Remove the contradictions and the redundancy, then test against revision four as a baseline

Explanation

The principle — Prompts accumulate. Each revision is added under pressure to fix one observed failure, and nobody removes anything, so a prompt that has been iterated many times tends to acquire contradictions and repetition that no single edit introduced.

Why the key is correct — Google's prompt-health checklist names both faults present here as distinct items to remove. Conflicting instructions and examples: audit the prompt for logical contradictions or mismatches between instructions or an instruction and an example. Redundant instructions and examples: look for the same instruction or concept stated multiple times in slightly different ways without adding new information or nuance. Neither is described as something to arbitrate or outweigh — both are things to take out. The second half of the key matters as much as the first. Google frames prompt engineering as a test-driven and iterative process, and revision four is a known-good reference point, so testing the cleaned prompt against it converts "this feels better" into a comparison. Without a baseline, revision twelve is just another sentence added under pressure.

Why the others are wrong — Rewriting from scratch discards eleven revisions worth of hard-won knowledge about how this task gets misread, which is exactly the information a fresh prompt lacks. Adding a priority rule leaves both contradictions standing and makes the prompt longer, when the checklist's remedy is removal. Rolling back is a sensible emergency measure and would restore quality today, but it also throws away seven revisions of learning and leaves the accumulation pattern free to repeat.

Remember this — Iteration should subtract as often as it adds, and every clean-up needs a baseline to be measured against.

Sources — Google Cloud, Overview of prompting strategies.

Sources

Primary sourceOverview of prompting strategies — Google Cloud · accessed 9 Aug 2026
“Look through the prompt and examples to see if the exact same instruction or concept is stated multiple times in slightly different ways without adding new information or nuance.”
Primary sourcePrompt design strategies — Google · accessed 9 Aug 2026
“Prompt design can sometimes require a few iterations before you consistently get the response you're looking for.”

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