Observe a provider cost

Declare what the intent can know near the Node or Tool, then observe the actual cost at the point where the external effect or consumption is actually known.

Rules

• Do not automatically copy a Node's economic contract onto a Tool that shares its handler.
• Missing observation never means zero cost.
• An observation has a stable key and semantics fact, delta, or cumulative.
• Amounts distinguish engaged et observed.
• The provider helper reports the fact; it does not choose its economic parent.
• Avoid double counting when multiple layers share the same provider effect.

See Economic contracts and the V1 reference.