Let me frame my situation. At the moment, I write my master thesis (pure mathematics). According to my advisor, the content of my thesis is already "good enough". But I still feel that the content is not adequate, especially if one wants to pursue an academic career. Until now, I carefully explained a proof of the theorem in a research paper. Moreover, my advisor seems to be rather restrictive with improvements and recommendations, even if I directly ask him.
So I would like to ask the Academia.SE community, if they have recommendations what a (very) good master thesis should contain.
Is this question on-topic for this community?