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

> Source: <https://dev.to/jefferson999/my-agent-looked-fine-until-i-gave-it-an-empty-list-1g56>
> Published: 2026-10-31 04:40:10+00:00

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:

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/](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.