agent_loop_handlingTier 1 · 70% confidence

ai-agents-agent-loop-handling-agent-loops-indefinitely-with-invalid-format-missi-3a62bcec

agent: ai_agents

When does this happen?

IF Agent loops indefinitely with 'Invalid Format: Missing Action:' after 'Thought:' error when no tool is needed, due to malformed custom format instructions.

How others solved it

THEN Ensure format instructions include a clear stop token, such as 'Final Answer:' or 'AI:', after the 'Thought: Do I need to use a tool? No' line. Also set a reasonable max_iterations (e.g., 5) as a safety net. Do not rely solely on the model's ability to stop; use the agent's built-in termination logic.

FORMAT_INSTRUCTIONS = '''Thought: Do I need to use a tool? Yes\nAction: the action to take\nAction Input: the input\nObservation: the result\n...\nThought: Do I need to use a tool? No\nFinal Answer: [your answer here]'''

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