If GPT makes up the parameters, then instruct it in the system message to only call the function(s) if it can be inferred from the users request, else start follow-up questions to clarify missing parameters.
Be very strict with the instruction. Use words/sentences like “It is mandatory …”, “strictly follow …”, etc.
Be positive with the commands. Avoid negative sentences like “You are not allowed to …”, “Do not …”, etc.
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