Chemical tests given by glucose (biomolecule)
This are two different types of reactions. 

Tollens is a redox reaction in which silver is reduced and glucose is oxidized. 
This reaction depends on the redox potential of glucose only. 

Schiff and bisulphite tests are addition reactions. The reagents condense with the aldehyde group. 
This occurs also in the case of glucose but it is not sufficient to give a positive result. 
In the case of bisulphite, the adduct must precipitate, but it is too soluble. 
In the case of the Schiff test, the adduct must dehydrate, but it forms the glucosamine derivative instead.