A system improves grammar and punctuation and the teacher considers the text to be mature. I propose to distinguish formal correctness and quality of the argument.
In the example, a well-written sentence contains an unproven statement. The activity can ask the student to motivate a passage and indicate a source.
Language review may reduce a barrier, but it does not automatically produce knowledge. A consistent assessment recognizes the useful support and separately controls the competence that the task intends to develop.