The Cost Model Uber Published, and the Line It Left Out
Unit-cost engineering at hyperscale worked exactly as designed and the invoice still multiplied, which is the arithmetic your own agent budget is walking into this quarter.
Decompose the spend into four factors
What Uber's engineering team published is an observability schema first and a finance number second. Each factor has its own owner and its own lever: session count sits with product, turns with the agent loop, tokens with prompt construction, price with procurement. A blended dollars-per-request figure is unattributable the moment it moves, because the line goes up and any of six things could have moved it. That schema is worth copying even by teams that reproduce none of the optimizations.
The forecasting use is sharper than the reporting use. Once spend is multiplicative, unit-cost work and demand growth are separate terms compounding against each other, and the elasticity here was brutal: unit cost fell by roughly a third, demand made it back more than nine times over. An efficiency program presented to finance without the absolute-spend series beside it loses the budget argument the following quarter, however good the ratio looks.
Code-mode batching saves tool tokens
Code-mode batching, where the agent emits code that calls tools so results never round-trip through the context window, is credited with saving 55-100% of tool-execution tokens. The width of that range is itself the finding: it signals severe workload heterogeneity, and 100% definitionally means no tool result ever entered context, which holds for one narrow class of workflow. Measure the local distribution rather than adopting the headline, with a task-success guardrail attached, because token savings that depress completion rate are negative ROI wearing an efficiency label.
Progressive disclosure is the companion lever. With 1,000+ MCP tools registered against a 24-million-node, 80-million-edge context graph, tool-schema tokens scale linearly with catalog size, JSON schema competing with real task context inside one window. Token bills don't break out schema boilerplate, and at that catalog size it is most of the prompt; CLI-resolved tool discovery cuts it, while swapping in a cheaper checkpoint leaves it untouched.
Skill dispatch is a ranking problem with known metrics
3,600+ skills against 30,000+ executions per day averages roughly 8.3 executions per skill per day, which in practice is a power law with a long dead tail. The stated authoring rule, that a skill description is a router written in the words a user would actually type, is a top-k retrieval spec with the prose left on. Build a labeled query-to-skill dataset, report precision@1 and precision@3, gate catalog additions on regression. Description collisions arrive with scale, and teams without that eval spend weeks debugging a ranking failure as a model failure.
One number to discount: 70%+ of pull requests being agent-attributed is an attribution metric wearing a productivity metric's clothes, with no revert rate, no defect density, no review latency and no LOC normalization behind it.
Where the surrounding evidence lands
Two corroborations tighten this. The same company's database team documented static rate limiting and static quota management failing outright under hyperscale multi-tenant load before moving to adaptive load management. Most inference gateways still run that identical open-loop control: a fixed QPS cap per tenant on a workload whose cost per request varies by an order of magnitude with prompt and generation length. The fix is closed-loop concurrency control on observed queue delay, shadow-tested before enforcement.
On the platform side, analyst consensus reported by The Information puts Snowflake at $1.481B revenue (+29%) and MongoDB at $734.4M (+24%), with prints landing Wednesday and Tuesday. A consumption vendor compounding at a quarter to a third per year is a compute bill compounding at the same rate against a flat data budget. Salesforce reworking how it charges for AI is the second signal this quarter that per-seat margin models optimize an objective the invoice no longer uses.
Cost per successful task, multiplied by demand, is the only metric that reconciles with the invoice.
What to do
Instrument agent spend as the explicit factor model (users x sessions x turns x requests x tokens x price) in your observability stack this sprint, with absolute spend and unit spend on separate dashboards.
Run a controlled A/B of code-mode batching against per-call tool invocation on your highest-volume agent workflow within two weeks, reporting tool-execution tokens, task success rate, and p95 latency together.
Build a labeled query-to-skill dataset and report precision@1 and precision@3 as a regression gate before your skill catalog passes 50 entries this quarter.