Why can I not tell which sub-agent in my pipeline burned most of my budget?

Multi-agent AI pipelines are now standard: an orchestrator spawns specialist sub-agents that each call their own models, tools, and external APIs, and the resulting compute costs land in a single invoice with no line-item breakdown. Attributing token consumption to specific sub-tasks requires instrumentation that no major agent framework ships by default, leaving finance and engineering teams with aggregate spend figures they cannot route to the right business unit, product feature, or customer account. Outcome-based pricing models, such as charging per resolved support ticket, depend on knowing what each resolution cost at sub-agent granularity, but that data does not exist in any standard tracing or billing format today. Without it, the unit economics of agentic products are rough estimates, enterprise chargeback of AI costs to the right cost center is manual, and identifying which par