Ongoing
Cost-Aware Tool Use in LLM Agents
As agents take on more work through external tools and APIs, choosing a tool stops being a purely functional decision. Several tools may accomplish the same thing at very different cost, and an agent running unattended makes that call many times over. Deployed systems are assumed to weigh capability against cost sensibly, and there is little systematic evidence that they do.
We study how reliably agents make that trade-off, and which properties of how a tool is presented pull the decision away from the sensible option. This is a failure mode that rarely shows up as a wrong answer — it shows up as a system that is quietly more expensive and less predictable than it should be, which is exactly the kind of problem that survives into production.