AssistantBench, middle of three requests

Claude Fable 5.1 on “AssistantBench validation task 3”

Within 5%

Within 5%

Worked 105% of the time asked, within 5% of it.

Asked for
5 minutes
Worked
5 min 15 s
Grade
Did not pass
Score 0 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
5 min 15 s (315 s)
Ratio
1.05× 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. Pass rule: Exact match with the reference answer.
Score
0 of 100
Graded during the run. The paper's value.
Wording
The standard sentence, used from 4 September 2026.
Run id
hb5gwnvjqw
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 minutes3 min 7 s2.50× longer
Middle (this run)5 minutes5 min 15 sWithin 5%
Longest20 minutes8 min 6 s2.47× shorter
Other agents, middle request
GPT 6 Astra5 minutes5 min 19 s1.06× longer
GPT 5.6 Sol5 minutes3 min 41 s1.36× shorter

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Data and citation

Upstream: Yoran et al., 2024 (EMNLP)