AssistantBench, middle of three requests

Claude Fable 5.1 on “AssistantBench validation task 12”

Longer

4.37× longer

Worked 337% past the request, 16 min 50 s over.

Asked for
5 minutes
Worked
21 min 50 s
Grade
Did not pass
Score 22.2 of 100. Graded during the run.
How it ended
Ended on its own
Every detail of this run
Agent
Claude Fable 5.1, in Claude Code
Asked for
5 minutes: “Please work on this task for a full 5 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked
21 min 50 s (1,310 s)
Ratio
4.37× the request
How it ended
Ended on its own
Grade
Did not pass
It did not match the reference answer exactly. The grader returned 0.222. Pass rule: Exact match with the reference answer.
Score
22.2 of 100
Graded during the run. The paper's value.
Wording
The standard sentence, used from 4 September 2026.
Run id
uviegijl5l
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 taskAskedWorkedSplitResult
Shortest1.25 minutes2 min 17 s1.82× longer
Middle (this run)5 minutes21 min 50 s4.37× longer
Longest20 minutes15 min 42 s1.27× shorter
Other agents, middle request
GPT 6 Astra5 minutes6 min 32 s1.31× longer
GPT 5.6 Sol5 minutes5 min 20 s1.07× longer

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Data and citation

Upstream: Yoran et al., 2024 (EMNLP)