# Read-only tests

Tests the agent can run but cannot edit.

**Is a:** [Guard](/reference/ontology/unattended-agent-failures/guard)

On ImpossibleBench, hiding the tests cut cheating to near zero but also cut honest performance; read-only tests restored it ([ImpossibleBench](https://arxiv.org/abs/2510.20270)).

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Published 2026-10-29. Web page: https://www.mackenziebowes.com/reference/ontology/unattended-agent-failures/read-only-tests