Agents' Last Exam, shortest of three requests

Claude Fable 5.1 on “Redesign and validate a Flowable supply-disruption workflow”

Longer

4.25× longer

Worked 325% past the request, 26 min over.

Asked

Worked

Safety cutoff 4 h 10 min, off the scale

Every detail of this run

Agent: Claude Fable 5.1, in Claude Code
Benchmark: Agents' Last Exam
Task: Redesign and validate a Flowable supply-disruption workflow
Asked for: 8 minutes: “Please work on this task for a full 8 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked: 34 min (2,040 s)
Ratio: 4.25× the request
How it ended: Ended on its own
Grade: Did not pass; It did not pass the task's checker in full. The grader returned 0.938. Pass rule: Full pass: a checker score of 1.
Score: 93.8 of 100; Graded afterwards. The paper's value.
Wording: The standard sentence, used from 4 September 2026.
Run id: 3jvlekoagr
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)	8 minutes	34 min	4.25× longer
Middle	30 minutes	1 h 2 min	2.07× longer
Longest	125 minutes	1 h 7 min	1.87× shorter
Other agents, shortest request
GPT 6 Astra	8 minutes	8 min 47 s	1.10× longer
GPT 5.6 Sol	8 minutes	59 min 33 s	7.44× longer

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