My aplogies for being so insistent when it comes to naming, but if I just saw this type name without access to the source code, I would be puzzled. It's not so much that it's long, but more that it doesn't form a proper compound word, and it also doesn't really scan as a sentence.

Could we call it something like these alternatives?

- MutableValueTypeOpinion
- ThrowDescriptionAboutMutableValueTypeIssue
- MutableValueTypeWarningThrower