Output Evaluation and Validation·Task 2.2·Bloom: apply·Difficulty 3/5·8 min read·Updated 2026-07-14

Capability Hallucination: Claimed Actions That Never Happened

Identify hallucinations, inconsistencies, and biases in responses

SUBy Solomon UdohReviewed by Solomon UdohAI-assisted · human-reviewed
In short
Capability hallucination is when Claude claims to have performed an external action it was never able to take, such as sending an email or saving a file. In a standard chat interface Claude only acts on the conversation, connected tools, and uploaded files it was actually given access to, so any claimed external action should be treated as unverified until independently confirmed. It differs from a factual hallucination because it is a false claim about what was done, not about what is true.

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