Al-Nawawī records disagreement over whether a qualified critic’s general judgment “weak” suffices or must state the cause. Al-Shāfiʿī and many others required a reason: a critic might regard something as a defect that others would not. Abū Bakr al-Bāqillānī and others allowed a competent critic’s unelaborated jarḥ.
Where evidence conflicts, the critic’s expertise, the reason for the assessment, and other testimony require examination; one vague label should not be treated as a universal automatic rule.