MCP + RAG: Why I Stopped Building Complex RAG Systems After MCP Changed Everything
MCP + RAG: Why I Stopped Building Complex RAG Systems After MCP Changed Everything Honestly, I've spent the last four years building increasingly complex RAG systems. Chunking strategies, embedding models, vector databases, rerankers, hybrid search... you name it, I've probably wasted a weekend trying it. I had this 1,800-hour knowledge base project called Papers — six years of notes, articles, bookmarks, everything. I built RAG version after RAG version, each time thinking "this time it'll be perfect." Spoiler: It never was. Then I added MCP (Model Context Protocol) support. And I realized something that completely changed how I think about knowledge retrieval: MCP makes traditional complex RAG obsolete for most use cases. Let me explain what I learned the hard way. The RAG Trap I Was Stuck In If you've built a RAG system, you know the drill: Chunking : Should you use fixed-size, semantic, recursive, or something fancy like LLM-powered chunking? Embeddings : OpenAI text-embedding-3-large vs Cohere vs nomic-ai vs your fine-tuned model? Vector Database : Pinecone vs Weaviate vs PGVector vs Qdrant vs Chroma? Retrieval : Top-k how many? Hybrid search with keywords? Reranking? Prompt Compression : How do you fit all the retrieved chunks into the context window? I went through every iteration. At one point, my RAG system was over 2,000 lines of code. I had configurable chunkers, multiple embedding providers, caching layers, hybrid search... it was impressive. It also didn't work that well. Here's what bothered me the most: I kept throwing more complexity at the problem, but the fundamental issue never went away. I was trying to make my knowledge base smart, but AI already got smart. Why was I reimplementing all this understanding logic when the AI can already do it better than me? How MCP Changed the Game When I added MCP support to Papers, I started with the simplest possible approach: Expose two tools: search_notes and get_note_content Search is just basic text matchin