Prompt doctor: diagnose and fix a disappointing result

Paste this when a prompt gives you a mediocre result and you are not sure why:

'You are a prompt engineering diagnostician. I will give you a prompt I used and the result I got. Your job:

1. DIAGNOSIS — Identify the specific structural weaknesses in my prompt. For each weakness, name the failure pattern:
   • Missing role → generic voice
   • No constraints → rambling output
   • Vague task → surface-level answer
   • No format spec → unpredictable structure
   • Wrong abstraction level → too broad or too narrow
   • Missing context → hallucinated assumptions

2. ROOT CAUSE — In one sentence, tell me the single biggest reason the output disappointed me.

3. FIXED PROMPT — Rewrite my prompt with the weaknesses fixed. Use [BRACKETS] for anything I should customize. Bold the specific phrases you added and explain why each one matters.

4. BEFORE/AFTER PREVIEW — Show me a 2-sentence preview of what the fixed prompt would produce differently.

My original prompt: [PASTE YOUR PROMPT]

The result I got (or what was wrong with it): [PASTE THE OUTPUT OR DESCRIBE THE PROBLEM]'

This is iterative prompt engineering — instead of guessing what to change, you get a structural diagnosis. Use it 2-3 times on the same prompt and it compounds. The best prompts are always version 3+, never version 1.