Iterative DebuggingAdvanced

Iterate on Prompts, Not Outputs

When Claude's output is wrong, most people re-run or rephrase the same prompt. Instead, diagnose WHY it failed and add a targeted constraint.

iterationdebugging-promptsrefinement

The Strategy

Vague re-runs produce random variation. Diagnosing exactly what went wrong and adding a precise negative constraint gives you deterministic improvement, not a slot machine.

prompt.txt

// Bad iteration (repeating yourself):
"Try again but make it better"

// Good iteration (targeted fix):

// Observation: Claude added unnecessary comments
// Targeted constraint added:
<constraints>
<add>Do NOT include any inline comments or JSDoc</add>
</constraints>

// Observation: Claude used a class instead of a function
// Targeted constraint added:
<constraints>
<add>Use only arrow function expressions—no class keyword permitted</add>
</constraints>

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PromptingBeginner

Use Negative Constraints

Tell Claude what NOT to do. "Do not add comments", "Do not use any external libraries" — negative constraints are just as powerful as positive ones.

constraintsguardrailsfocused-output

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Iterative DebuggingBeginner

The Error → Fix → Verify Loop

Structure debugging sessions as a tight loop: paste the error, get a fix, verify with the exact command, repeat.

debuggingerrorsloop

View snippet