Section 2

MCP Primitives

This section carries the ticketdesk server's tools, resources and incident-summary prompt across the 2026-07-28 wire, then examines the wire itself. The model calls tools, the application chooses resources and a person invokes prompts, and each primitive brings its own costs and attacks, from a five-server tool catalog that fills 30% of a 200,000-token context window to a resource path that escapes its directory. Traces captured from the official Python SDK, real servers from GitHub and the MCP project, and documented CVEs supply the numbers.