Left of the Loop: The Astrolabe

An astrolabe doesn’t map every star. It gives you a way to find your position relative to the ones that hold still. That’s the instrument I reach for when someone asks which AI tool they should be using. The honest answer is that the tools will be different in six months. The layers won’t. I spent a week trying to make sense of a handful of names that kept showing up in the same conversations. Tessl . Goose . Archestra . Kestra . Modelplane . RAG , MCP , half a dozen others orbiting nearby. Each one has its own pitch, its own funding round, its own reason it’s the thing you should adopt next. Taken together they read like noise. Taken apart, they sit on different floors of the same building. The agent loop again, the one I keep coming back to. Once you place each tool on a floor, the noise turns into a map. Tessl sits left of the loop , at the intent layer. Turn a spec into something an agent runs against directly. This is the one tool on the list that pushes back instead of going along with it. A well-formed spec is not the same thing as a team that agrees on what the spec means. The Agora produces the second thing as a byproduct of producing the first. Tessl produces the first and assumes the second follows. It doesn’t, automatically. That’s the whole argument. RAG and MCP are plumbing. Protocol, not position. They carry context into the loop and don’t take a side in any argument about who should be in the room when the spec gets written. They’re also the one floor with an actual standard. MCP, A2A , ACP , all under Linux Foundation governance now, joint working groups, cross-protocol commitments. Passing data between systems is a solved problem with decades of precedent behind it, so it standardized almost on contact. Nothing else on this floor plan has that. Governance, orchestration, the harness, the spec layer: every vendor is still building its own version and calling it the obvious one. The standard showed up first at the floor that mattered least to this ar