What 80% AI-written test pipelines actually cost

MCP is the boring middle that makes any of this work. The cliché is that MCP is “USB-C for AI”: one open protocol, any tool. Like most analogies, it is about eighty percent right. The part that matters is the eighty: I do not have to write a custom adapter for every system the agent talks to. One MCP server per tool and every agent talks to all of them the same way.
Typed handoffs between agents are my own architecture, layered on top of MCP rather than provided by it. Each agent writes a typed artifact the next agent reads. Each handoff is logged with provenance. When something went wrong six stages in, I could replay the chain. Without that discipline, a multi-agent pipeline is a debugger’s worst day. You know the test plan is wrong. You cannot tell whether the mistake came from the Figma read, the requirements interpretation or the ticket scaffolding. With it, I could point at exactly which stage went sideways and which inputs it was looking at when it did. The pattern lives in a public MIT-licensed reference implementation for any reader who wants to run it.
The sixteen-minute number is the marketing number. I ran the full chain end to end in about sixteen minutes on a synthetic net-new screen, Figma in, automation suite out. That repeated across my runs; it is not a demo trick. But sixteen minutes is the part of the story most fun to tell and least useful to learn from. It is what gets quoted in the all-hands. The hours that come after, when a human reviews each handoff, are where the work actually lives.