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