You added input validation. Your agent fabricated a record that does not exist in any database. You added a guardrail hook. Your agent selected the wrong tool and returned made-up data. You added prompt instructions. Your agent bypassed a payment requirement because the LLM decided to "make an exception." Each fix solved one problem and left four others wide open. AI agents do not hallucinate in one way. They hallucinate in five: fabricating data when retrieval returns nothing, selecting wrong tools when descriptions overlap, ignoring business rules the LLM treats as suggestions, failing to adapt when soft constraints are violated, and bypassing financial and legal requirements that must never be overridden. A single guardrail cannot cover all five. Each failure mode requires a different defense. I will walk through five techniques that form a layered system: graph-based retrieval that computes answers from structured data instead of guessing (zero fabrication on knowledge queries), semantic tool routing via protocol-based discovery that replaces brittle keyword matching (correct tool selection without custom vector indexes), database-driven steering rules you update in seconds without redeploying the agent, STEER messages that guide agents to self-correct instead of hard-failing on soft constraint violations (15 guests requested, agent adjusts to 10 and informs the user), and framework-level hooks that block operations the LLM must never bypass regardless of how it reasons.

Outline: • Your AI Agent Hallucinates in 5 Different Ways • Grounded Retrieval with Graph Queries • Semantic Tool Routing • Steering Rules + STEER Messages • Hard Hooks That Cannot Be Bypassed • Full Layered Defense Test • Resources + Q&A