A system where an LLM plans and executes actions toward a goal using tools, memory, and feedback loops.
Agents expand surface area and risk. PMs define scope, stopping rules, and observability. The payoff is faster delivery and fewer manual steps; the risk is runaway actions, cost spikes, or policy breaches. KPIs include task success rate, cost per task, and time-to-complete.
Start narrow: one clear goal, few tools, explicit stop conditions. Add step-level logging and replay. In 2026, pair agents with safety rails, per-tool budgets, and a lightweight overseer that can abort or request confirmation on high-risk steps. Ship with evals that mirror the full multi-step journey, not isolated steps.
A growth agent researches competitor pricing, drafts a comparison email, and schedules A/B tests. With tool budgets and approvals for send actions, it achieves 72% task success while keeping cost under $0.18 and p95 completion time under 90 s.