Why not test its ability to negotiate and trade, as well as to improvise in human behavior? If it can write you a poem for some money, then invest that money in the stock market, and later use the resulting fortune to benefit itself (an upgrade, perhaps?), then you’re probably dealing with an intelligent being, no? Bonus points if it studies other methods of succeeding, and is willing to benefit other intelligent beings.
Why not test its ability to negotiate and trade, as well as to improvise in human behavior? If it can write you a poem for some money, then invest that money in the stock market, and later use the resulting fortune to benefit itself (an upgrade, perhaps?), then you’re probably dealing with an intelligent being, no? Bonus points if it studies other methods of succeeding, and is willing to benefit other intelligent beings.