A tool (30) for a microinvasive surgical instrument includes a body member (40). A proximal end (41) of the body member is mechanically connected to or is configured to be mechanically coupled to a distal end (16) of a shaft (14) of a microinvasive surgical instrument (10). A first jaw (50) has a mechanically articulated connection to the body member. A second jaw (60) has a mechanically articulated connection to the body member. The first jaw and the second jaw are configured to be pivoted independently from each other. The second jaw provides the shape of a ‘；U’； or ‘；O’； at least partially encircling a fenestration (61). The tool provides open configurations, each with an angular distance between the first jaw and the second jaw. The tool provides a closed configuration with the first jaw at least partially accommodated in or capping the fenestration of the second jaw.
