In Part 1 , we explored why modern AI systems need more than carefully written prompts. In Part 2 , we looked at tokens, context windows and memory and why simply adding more context doesn't necessarily produce better results. In Part 3 , we went one step further: RAG helps retrieve relevant information. Tool Calling lets an AI application interact with external systems. MCP provides a standardized way for AI applications to interact with tools. But there's one ...