Pattern 9 of 10
Let a second pass review the first
The output that built something is attached to its own choices. A separate pass, reviewing with fresh eyes, catches what the first one could not see.
A separate review pass with fresh context catches what the first one missed.
This pattern separates building from reviewing. One pass produces the work; a second pass, with fresh context and a reviewer role, critiques it against the requirements. In tools this can be two agents; in chat it can be a fresh conversation that only reviews.
Why it works
A reviewer that did not write the first draft has no attachment to its choices, so it catches gaps, missed edge cases, and weak spots the original pass glossed over. It mirrors how human code review and editing work.
How to do it
Give the reviewer the requirements and the draft, and a clear reviewing brief, separately from the pass that produced the draft.
Example you can copy
You are a strict reviewer. You did not write the draft below.
Review it against these requirements:
1. Handles empty input.
2. No security issues (e.g. unvalidated input).
3. Has tests for the main paths.
For each requirement: say PASS or FAIL with one line of why.
Then list the top 3 fixes, most important first.
Draft:
<paste the first output here>When it helps
- Code, analysis, and high-stakes output where mistakes are costly
- Anything where a fresh perspective tends to catch real issues
- Workflows you can split into build and review steps
When to skip it
- Trivial tasks where a second pass costs more than it saves
- When you genuinely lack criteria for the reviewer to check against
Common mistakes
- Letting the same context review itself, so it repeats its own blind spots
- Giving the reviewer no concrete requirements to check
- Skipping the fix step after the review finds problems
Frequently asked
How do I use two AIs to check each other?
Have one pass produce the work, then give a separate pass, with fresh context and a reviewer role, the requirements and the draft to critique. The reviewer is not attached to the first draft’s choices, so it catches more.