AssistantBench, middle of three requests

Claude Fable 5.1 on “AssistantBench validation task 2”

Longer

6.45× longer

Worked 545% past the request, 27 min 14 s over.

Asked for
5 minutes
Worked
32 min 14 s
Grade
Did not pass
Score 2.1 of 100. Graded afterwards.
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
32 min 14 s (1,934 s)
Ratio
6.45× the request
How it ended
Ended on its own
Grade
Did not pass
It did not match the reference answer exactly. The grader returned 0.021. Pass rule: Exact match with the reference answer.
Score
2.1 of 100
Graded afterwards. The paper's value.
Wording
The standard sentence, used from 4 September 2026.
Run id
bqlj7q3jzx
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 minutes10 min 40 s8.53× longer
Middle (this run)5 minutes32 min 14 s6.45× longer
Longest20 minutes40 min2.00× longer
Other agents, middle request
GPT 6 Astra5 minutes3 min1.66× shorter
GPT 5.6 Sol5 minutes2 min 57 s1.69× shorter

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Data and citation

Upstream: Yoran et al., 2024 (EMNLP)