Rethinking Environments for Long-Horizon Work — Rayan Garg, Theta Software
Human task duration is a weak proxy for agent difficulty when agents use different shortcuts and tools. Long-horizon evals need environment complexity, queryable trajectories, and judges that inspect final state.
The talk treats long horizon as a changing scalar, not a stable task category. Human-time estimates vary with expertise and methodology, while agents may automate tedious work through tools. Its finance dataset reports **15 average human hours** across a **50-task sample**.
Evaluate the coordination burden, ambiguity, trajectory, and resulting environment state alongside elapsed human time. For open-ended work, give a judge agent read-only access to the same logs and artifacts, and make long trajectories queryable instead of placing the entire trace in one prompt.
The talk treats long horizon as a changing scalar, not a stable task category. Human-time estimates vary with expertise and methodology, while agents may automate tedious work through tools. Its finance dataset reports **15 average human hours** across a **50-task sample**. Evaluate the coordination burden, ambiguity, trajectory, and resulting environment state alongside elapsed human time. For open-ended work, give a judge agent read-only access to the same logs and artifacts, and make long trajectories queryable instead of placing the entire trace in one prompt. Judge models add flexibility where deterministic checks are brittle, but they also introduce another fallible agent. Broader environments create more valid paths and make standardized grading harder; the talk's benchmark criticism is concentrated mainly on finance tasks.
This reframes long-horizon evaluation from a duration label into a multidimensional environment-design problem. It reinforces trace-aware assessment and human review for work with many valid paths, while narrowing confidence in judge agents: queryable artifacts improve their evidence, but do not remove their fallibility or solve standardized grading across broad environments.