It makes no judgments about the work, nor does it provide results or conclusions of the research.
Critical abstracts are generally 400-500 words in length due to the additional interpretive commentary. A descriptive abstract indicates the type of information found in the work.
Then ask yourself: if your abstract was the only part of the paper you could access, would you be happy with the amount of information presented there? If the answer is "no" then the abstract likely needs to be revised.
A critical abstract provides, in addition to describing main findings and information, a judgment or comment about the study’s validity, reliability, or completeness.
College assignments, specifically the requirements when writing papers, can cause confusion for new students.
Both forms of relaying information are utilized for different reasons but can be found within the same writing piece on occasion.