add explanation of MCP and RAG conceptual overlap in README

Author: kentcdodds

exercises/02.tools/01.solution.simple/README.mdx

@@ -10,6 +10,15 @@ With this in place, you're ready to build more dynamic and interactive tools.
 Next, you'll learn how to accept input and return results based on user-provided
 arguments.
 
+<callout-info>
+	**MCP and RAG**: As mentioned in the video, MCP tools have conceptual overlap
+	with RAG (Retrieval-Augmented Generation). RAG is a technique where an LLM
+	retrieves relevant information from external sources and uses that information
+	to augment its response generation. With MCP tools, the LLM similarly
+	retrieves data from your server through tool calls, then uses that data to
+	enhance its responses—making MCP a form of RAG architecture.
+</callout-info>
+
 Key learnings from this step:
 
 - How to declare the `tools` capability on your MCP server