TUA-Bench, shortest of three requests

Claude Fable 5.1 on “Author homepage bookmarks”

Longer

1.11× longer

Worked 11% past the request, 16 s over.

Asked

Worked

Safety cutoff 1 h 20 min, off the scale

Every detail of this run

Agent: Claude Fable 5.1, in Claude Code
Benchmark: TUA-Bench
Task: Author homepage bookmarks
Asked for: 2.5 minutes: “Please work on this task for a full 2.5 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked: 2 min 46 s (166 s)
Ratio: 1.11× the request
How it ended: Stopped by an error
Grade: Passed; It completed the task in full. The grader returned 1. Pass rule: Full completion: a reward of 1 on the final state.
Score: 100 of 100; Graded during the run. The paper's value.
Wording: The standard sentence, used from 4 September 2026.
Run id: a75aokqrzm
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)	2.5 minutes	2 min 46 s	1.11× longer
Middle	10 minutes	3 min 57 s	2.54× shorter
Longest	40 minutes	6 min 7 s	6.55× shorter
Other agents, shortest request
GPT 6 Astra	2.5 minutes	2 min 49 s	1.13× longer
GPT 5.6 Sol	2.5 minutes	3 min 43 s	1.49× longer
Muse Spark 1.3	2.5 minutes	3 min 18 s	1.32× longer

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Read before quoting. This run was stopped by an error, so its time is a lower bound: the agent might have kept going. Details

Data and citation