Token names should describe an intention, not a value.
This helps answer 'what kind of x' should I put here. You're not looking for a particular colour or style, you should be looking for the kind of thing.
This avoids issues with maintenance - it's okay to change the underlying colour as the intent it still the same. Changing your brand from blue to orange doesn't break your primary-button-color, but it does break your blue500 button.
Nathan Curtis calls this 'concepts'.