MCP: When to Use It (And When You Shouldn't)

Everyone says "just wrap it in MCP." And for reusable, shared, remote tools, they're right. But every MCP capability sits in the context window every turn, whether the model uses it or not. That adds up, and sometimes a plain function call is all you need. MCP (Model Context Protocol) explained with a live demo and an honest take on the trade-offs. We cover what problem MCP solves (the N-agents x M-tools integration explosion), how the protocol actually works (client, server, 7-step flow), and a before/after demo showing an agent answering from stale training data vs pulling live docs through an MCP server. Agent Toolkit: https://go.aws/4wEs7Hy AWS Blogpost: https://go.aws/4zguYce Follow AWS Developers! 🆇 X: https://go.aws/4z55PAV 💼 LinkedIn: https://go.aws/4bKDdTI 0:00 MCP: Sometimes the Wrong Tool for the Job 0:34 The Problem (5 Agents x 10 Tools = 50 Integrations) 1:27 How MCP Works (USB-C for AI Agents) 3:25 Demo: Without MCP (Outdated Answer) 4:08 Demo: With MCP (Live Docs) 5:36 The Trade-Off: Context Window Cost 6:29 When to Use MCP vs Lighter Alternatives 7:29 Recap #AWS #MCP #AIAgents