Which word best describes the manner of action implied by 'unduly'?

The word 'unduly' implies an action or state that is more than what is considered appropriate or acceptable. When something is described as undue, it suggests that it exceeds the necessary or reasonable limits. Therefore, the word that best captures this concept is excessive. It indicates that the degree of action or effect is beyond what is warranted or justified.

In contrast, justifiable indicates that an action is reasonable or warranted, which is opposite to the implication of 'unduly.' Constrained suggests a limitation or restriction, which does not match the sense of overstepping bounds conveyed by 'unduly.' Minimal conveys a sense of smallness or insignificance, which again is inconsistent with the idea of going too far. Thus, excessive is the most fitting descriptor for the manner of action implied by 'unduly.'