🧩 Runtime Snapshots #13 — The Scalpel and the Swiss Army Knife: 50k Tokens Before You Say Hello

TL;DR: MCP burns 45k+ tokens on tool descriptions before your first prompt. E2LLM = 0 tokens until you paste the UI snapshot. For CSS debugging — scalpel, not Swiss Army knife. Runtime Snapshots is a series about what happens when you give LLMs the actual runtime state of a UI — not the HTML source, not a screenshot, not a description. Start from #1 or jump in here. We covered the basic MCP cost argument back in September . This is the architectural explanation of why it happens. Before your AI assistant reads a single line of your code, it has often already consumed 40,000–50,000 tokens . That's not a bug in your setup. That's MCP working as designed. What MCP Actually Loads Model Context Protocol is a genuinely useful standard. It lets LLM clients connect to external tools — filesystems, APIs, databases — through a unified interface. But "unified" has a heavy tax. When you connect a typical MCP server to your AI client (like Claude Desktop or Cursor), the protocol negotiates a sessio