The #1 Mistake People Make Building An AI Agent

Most people who build their first AI agent end up rebuilding it.

They jump straight into the tool, start connecting things up, and end up with something that technically runs but doesn't fit how their business actually works. I made that mistake. I had no brief, and I hadn't thought through which decisions the agent would handle on its own versus when it should stop and wait for me.

Write a one-page design doc before you build. What does the agent do? What does it decide on its own? At what exact point does it stop and hand the decision back to you? One page of answers to those questions is the spec. An agent without a defined stopping point will loop and cost you money, or make a wrong call and cost you trust.

Once you have that brief, Claude Code does the heavy lifting. Give it the spec and it writes, tests, and deploys the agent for you. You don't need a visual workflow builder anymore.

Then add guardrails before you let it run unsupervised. Decide what the agent does when it hits something it wasn't built for. A clear fallback, usually stopping and flagging it to you, keeps a small surprise from turning into an expensive one.

The design step feels like delay, but it's the one that stops you from rebuilding the same agent three times over.

Get the brief written before you open any tool.