My agent looked fine — until I gave it an empty list

Chery jefferson C — Sat, 31 Oct 2026 04:40:10 +0000

I built a small tool to test my own AI agent in 10 minutes, instead of trusting that it "looked right."

One test from it: "Handle an empty average." The starting code divides by the list length, so an empty list breaks it. The check is simple: handle an empty list safely, keep the normal average, and explain the empty-list behavior.

I ran two answers through it:

A fixed answer — check for an empty list first and return 0, otherwise return the normal average — scored 4/4. What-to-fix: "No fix needed for this task."
The original, unfixed function scored 3/4. It lost the "Is correct" point. The plain-language fix: tell the agent to check for an empty list first and return 0, and keep the normal average for everything else.

That is the whole point of the tool. It scores 4 things per task: finished, correct, did not make things up, and took no wrong action. Auto-score suggests, you confirm — so you get speed without handing the judgment to a black box.

The tool has 20 tasks: 10 developer, 5 personal-life, and 5 creator. It is free, with no API key, no login, and nothing leaves the page. It is a quick first check, not a CI or production replacement — use it first, then graduate to heavier tools when you need them.

Try this one task yourself: https://jefferson999.github.io/agent-reliability--score/

Paste your agent's answer, see the score, and read what to fix. If your agent passes the empty list, try the other 19.

DEV Community: Chery jefferson C

My agent looked fine — until I gave it an empty list