Question
You have a Microsoft Foundry project that contains a high-traffic agent.
After a recent update, operational costs increase significantly.
Monitoring confirms that the volume of user traffic to the agent remains unchanged.
You suspect that changes to the request or response characteristics are causing the increase. You need to identify whether the additional costs are driven by the model input size, the model output size, or expanded tool usage.
Which observability capability should you use?
- A. latency
- B. evaluation metrics
- C. run success rate
- D. token usage Correct
Explanation
Token usage reports input tokens and output tokens separately, so it shows directly whether requests or responses have grown, and tool definitions also count toward prompt tokens, so added tools appear there as well. Latency measures response time, not what is being consumed. Evaluation metrics measure response quality, and run success rate only shows whether runs complete, so neither explains a change in cost.
