Anti-Patterns

An AI model does not need retrieval for every question. The important problem is knowing when its internal knowledge is no longer enough. The Retrieval Trigger is a practical decision boundary that determines when an AI system should stop relying solely on model knowledge and obtain external evidence before answering.

An LLM does not magically know your files, databases or APIs. This practical continuation of the RAG series shows, with simple Python, how external data becomes retrievable evidence: from text files and SQL to full-text search, embeddings, context assembly and the final LLM call.

RAG sounds complicated, but the idea is simple: before an AI answers, it first looks up useful information from a knowledge source and gives that information to the language model. This guide explains RAG, LLMs, state, memory and tools using one simple mental model.