Northern Ostyak (Uralic) has optional object agreement. This paper analyzes the grammatical behavior of objects that trigger agreement and objects that do not, and demonstrates that while the former participate in certain syntactic processes, the latter are syntactically inert. The asymmetry cannot be explained with reference to semantics or argument status, as both objects bear an identical argument relationship to the predicate. Following the functional approach to language, under which the clause has three independent representational levels (syntax, semantics, and information structure), I suggest that the two objects differ in their information structure status. The object that does not trigger agreement bears the focus function, and systematically corresponds to the focus position. It is further argued that virtually all grammatical relations in Ostyak demonstrate reduced syntactic activity when they are in focus. This leads to a search for an information structure-driven motivation for certain behavioral properties.