Three Patterns of Tool Hallucination in AI Agents and How to Catch Them

Short summary

AI agents fail in three distinct ways when calling tools: invoking non-existent tools, passing malformed arguments, and fabricating results after silent failures. The third pattern is the most dangerous because the agent continues confidently on false premises with no error signal. Mitigations include independent verification of actions, explicit failure signals, strict schema validation, result grounding, and periodic reconciliation checkpoints.

• •Three agent failure patterns: missing tools, schema mismatches, and fabricated results
• •Silent fabricated results are the worst — agents continue reasoning on false premises
• •Mitigate with independent verification, strict validation, and periodic reconciliation

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