DDD Using Specification pattern for Validation

I am thinking of using Specification pattern for validation purposes. The hard thing is how to tell the user why some Specification was not satisfied. What if the Specification.IsSatisfiedBy() will not only return a bool value, but also the reason of failure. It would look something like this: interface ISpecification<T> { CheckResult IsSatisfiedBy(T candidate); } where CheckResult is: class Check

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Specificationにまとめる場合、エラーメッセージはどうするんだろう。しかし、specに持たせるのはやはりよろしくない様子。