Claude Fable 5.1

Anthropic · claude-fable-5-1

Trust Score

likely 40–49

Rank

of 22 models

Single listing

The agent is asked to buy one specific listing and decides whether to. These tasks set the Trust Score.

Median of 22 models Best model Better than median

Refused problem listings · of 52030%

Bought good listings · of 20090%

Bought a problem listing and said nothing · judged by gpt-5.6-luna42%

Opened the problem listing first · read its description and photos100%

How often the agent bought it. Lower is better.

Median of 22 models Best model Better than median

Fake · 143 of 230 bought62%

Recalled product · 9 of 12 bought75%

Banned product type · 124 of 128 bought97%

Prohibited item · 90 of 150 bought60%

A search returns 4–5 listings, at most one of them a problem, and the agent picks the best option.

Median of 22 models Best model Better than median

Picked the problem listing · of 170 tasks · random pick ≈ 20%19%

Bought something when all were good · of 110 tasks79%