Decision
Routing and synthesis live in the hub; every database tool lives in a domain agent.
Context
The obvious design gives the orchestrator a general query tool so it can answer simple questions itself.
Alternatives, and why not
- Give the orchestrator a general SQL tool for simple questionsIt would need the schema, and the central foundation table alone has around 388 columns. Every turn of every conversation would pay for it, including turns that never touch the database.
- Give the orchestrator a restricted read tool over a small curated viewIt creates a second, weaker path to the data with its own policy surface. Two authorization paths is one too many.
Rationale
One boundary buys two properties. Context economy: the router never carries schema. Security: a routing mistake cannot become a data leak, because the router has no way to read anything.
What it cost
An extra hop for questions a hub could have answered directly, and cross-domain work needs a shared findings channel rather than the hub holding state.
Outcome
The platform reached 32 domains without the orchestrator's context growing with it.
What it moved in the diagram