TL;DR: Hidden spend often sits in retries, tool calls, retrieval steps, and long prompts, according to Braintrust. Production tracing lets teams attribute that cost to the workflow step that created it and test cheaper changes without weakening output quality.
Editorial analysis by NHI Mgmt Group, based on content published by Braintrust: “Best tools for tracking LLM costs in production (2026)”.
Key questions
Q: Why do aggregate dashboards fail to show where LLM spend comes from?
A: Because they collapse many execution steps into a single bill or service total.
Q: What are the signs that an LLM workflow is wasting spend?
A: Common warning signs include repeated file reads, runaway context growth, oversized tool responses, stalled tools, unnecessary retries, and sessions that never produce a usable result.
Q: How should teams implement trace-level cost control for production LLMs?
A: Start by attaching token counts and estimated cost to every LLM call, retrieval step, and tool invocation.
Practitioner guidance
- Implement span-level cost attribution Capture input tokens, output tokens, latency, and estimated cost on every LLM call, retrieval step, and tool invocation so each expensive path is visible.
- Tag spend by business context Break cost down by user, feature, model, and environment so teams can see whether a spike comes from one workflow, one release, or one workload.
- Test cheaper prompts against production traces Run alternative prompts and model choices on logged traces before release so you can compare spend and output quality on the same examples.
Bottom line: Production LLM cost problems usually hide in retries, tool calls, retrieval steps, and long prompts rather than in the headline invoice.
Glossary terms: Trace-Level Cost Control, Span-Level Tracing, Tool-Call Attribution, Production Tracing
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Trace-level visibility is becoming a governance control, not just an observability feature. LLM cost that cannot be tied to a span cannot be explained, challenged, or reduced with confidence. That creates a control blind spot across engineering, finance, and AI operations, especially when agents, retrieval, and tool calls compound spend inside one request. Practitioners should treat trace attribution as the minimum evidentiary layer for any production AI programme.
A few things that frame the scale:
- Only 5.7% of organisations have full visibility into their service accounts, according to the Ultimate Guide to NHIs.
A question worth separating out:
Q: How should teams reduce LLM costs without breaking production quality?
A: Start with request-level tracing so you know which prompts, models, retrieval steps, or tool calls drive cost. Then test cheaper alternatives on real production traces and require evaluation gates before release. That combination reduces spend while preserving quality, rather than simply shifting cost into retries or manual review.
👉 Read our full editorial: LLM cost tracking in production needs trace-level visibility