Answer:
It is effective.
Explanation:
The claim is ineffective because it does not state a clear position.
It does state a clear position, (students should wear uniforms)
The claim is ineffective because it expresses a first person preference.
No mention of a first person preference in this statement.
The claim is ineffective because it suggests the essay will inform rather than argue.
It's rather clear the the person will argue for their claim, rather than inform the reader.
So by default, the answer must be that it is effective.