The right primitive for the task decides whether a workspace scales or collapses.

Most teams adopt GitHub Copilot as a single chat box, and it breaks at the second use case. This playbook treats routing as the first engineering decision: six primitives, agents, skills, plugins, MCP servers, hooks, and the configuration hierarchy, each with a boundary that decides whether the workspace scales. The payoff is measurable, roughly 30 percent less token spend per task, now billed in GitHub AI Credits, and output that stays consistent across the team.