Because the duties of Naidaijin, his authority, and the areas of which he could advise were extremely vague and abstract, to the degree that constitutional scholars are unable to clearly define them, it was an extremely special post, all of which depended on the person appointed and his trusting relationship with the emperor.
内大臣の職務・権限・助言できる範囲は、憲法学者ですら明確に定義することが出来ない程、非常に曖昧かつ抽象的なもので、全ては就任した人物と天皇の信頼関係のみで成立するという、非常に特殊なポストだった。