Choose the smallest useful job
Your first agent should own a narrow workflow: triaging inbound leads, drafting weekly summaries, routing support requests, or compiling research notes. A focused agent is easier to test, cheaper to run, and much easier to trust.
If you cannot describe the task in one sentence, it is probably too broad for a first build.
Design the control loop
A reliable agent usually follows a predictable pattern: receive input, gather context, choose an action, execute with guardrails, and report results. The trick is not making it smart everywhere. The trick is making it dependable in one lane.
Add tools deliberately. Every extra tool expands the failure surface, so start with read-only actions before granting write access.
Ship with instrumentation
Track how often the agent succeeds without intervention, where humans override it, and what kinds of prompts cause mistakes. Those metrics matter more than demo quality because they tell you whether the system is becoming operationally useful.
TL;DR Summary
- Start with one repeatable workflow, not a general assistant.
- Add tools only when the agent must read or write something real.
- Measure success by task completion, accuracy, and operator time saved.