Your AI Agent Isn't Stupid, Your Vector Database Math Is

Hey DEV community, CallmeMiho here. I’ve been auditing AI architectures all week, and I keep seeing developers blaming their LLMs for "hallucinations" when the model isn't the problem at all. Your AI agent doesn't have amnesia—your database is just failing at basic math. Retrieval-Augmented Generation (RAG) is the gold standard for AI Agents, but it has a hidden failure mode: Semantic Drift. Even if you upload the correct documents, your vector database might retrieve completely wrong "fragments