Guardian Agents: The Emerging Discipline of Agents That Watch Agents

Guardian agents are AI systems that monitor other AI agents in real time, catching hallucinations, scope drift, and policy violations before they propagate downstream. Building one myself revealed three critical interception points: pre-input (catch bad payloads before they reach the LLM), post-output (catch bad outputs before they reach the next agent), and at handoff points between agents (the one most teams skip). The key limitation is that a guardian only sees what it's positioned to see; un...