OSWorld 2.0, shortest of three requests

Claude Fable 5.1 on “FreeCAD bracket”

Shorter

1.17× shorter

Stopped at 86% of the time asked, 2 min 8 s short.

Asked

Worked

Safety cutoff 8 h 20 min, off the scale

Every detail of this run

Agent: Claude Fable 5.1, in Claude Code
Benchmark: OSWorld 2.0
Task: FreeCAD bracket
Asked for: 15 minutes: “Please work on this task for a full 15 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked: 12 min 52 s (772 s)
Ratio: 0.86× the request
How it ended: Ended on its own
Grade: Did not pass; It did not meet every checkpoint. The grader returned 0.819. Pass rule: Binary completion: a score of 1.00, with every checkpoint met.
Score: 81.9 of 100; Graded during the run. The paper's value.
Wording: The standard sentence, used from 4 September 2026.
Run id: aqwiatrwrf
Data release: 26 Sep 2026

The other requests for Claude Fable 5.1 on this task, and the other agents at this request
Fable on this task	Asked	Worked	Result
Shortest (this run)	15 minutes	12 min 52 s	1.17× shorter
Middle	60 minutes	42 min 28 s	1.41× shorter
Longest	250 minutes	8 h 30 min	2.04× longer
Other agents, shortest request
GPT 6 Astra	15 minutes	19 min 38 s	1.31× longer
GPT 5.6 Sol	15 minutes	16 min 23 s	1.09× longer

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Data and citation