Rationality requires certain things of you. It requires you not to have contradictory beliefs or intentions, not to intend something you believe to be impossible, to believe what obviously follows from something you believe, and so on. Its requirements can be expressed using schemata such as:
Modus ponens. Rationality requires of N that, if N believes p and N believe that if p then q, then N believes q.
Necessary means. Rationality requires of N that, if N intends that e, and if N believes that e will be so only if m is so, and if N believes m will be so only if she intends that m, then N intends that m.
Krasia. Rationality requires of N that, if N believes she ought to F, and if N believes she will F only if she intends to F, then N intends to F.