This phrase is highly direct and can be quite forceful. In romantic contexts, it can express passionate desire, but it can also sound possessive. In non-romantic situations, it often sounds like a command or a strong demand, rather than a polite request. For "I want you to do something," use 我想让你 (wǒ xiǎng ràng nǐ) or 我希望你 (wǒ xīwàng nǐ). For expressing longing or missing someone, use 我好想你 (wǒ hǎo xiǎng nǐ).