Principle
Give verification an independent evidence path
A second opinion is weak when it only rereads the first opinion.
When it fits
- The same agent that produced an artifact is also asked whether its own work is correct.
When to avoid it
- A separate model is not automatically independent. Shared data, prompts, tools or blind spots can still produce correlated errors.
Why it matters
Let the verifier inspect the artifact and evidence directly: run tests, query the system, open the source, inspect screenshots or recompute a result. Separating author and verifier can reduce shared incentives, but the larger gain comes from giving verification an evidence path that does not depend on the author's summary.
An example
A code agent says a page works. The verifier opens the deployed preview, runs the relevant tests and checks the requested behavior rather than asking the code agent to self-critique its explanation.
Check your result
At least one important acceptance claim is checked against independent artifact or system evidence.
Keep this limit in mind
- A separate model is not automatically independent. Shared data, prompts, tools or blind spots can still produce correlated errors.
Connected ideas
Useful withCombine grader types instead of asking one LLM judge to decide everything
Evidence and sources
Verification is stronger when the verifier can inspect evidence with tools and is not limited to accepting the generator's own explanation of success.
A separate verifier can share the same blind spots or bad evidence; independence is a design aid, not a proof of correctness.
What Does Done Even Mean? Agents and Paperclip's Liveness Model · 5:56-6:40, separate verifier from author, provide verification tools and make the next owner explicit