A cutter for a well construction tool has a
cutting structure affixed to a substrate, which defines a monotonically decreasing
diameter with respect to an
axial distance from an interface between the
cutting structure and the substrate. A shear surface formed in the
cutting structure intersects a surface of the cutting structure between the interface and an apex of the cutting structure, and defines a smaller angle with respect to a reference than the cutting structure
proximate the interface and a larger angle with respect to the reference than the cutting structure
proximate the apex. The apex is rotationally symmetric about a centerline of the cutting structure in all rotational directions, and a
radius of curvature of the apex is at most 75 percent of a
diameter of the substrate. A well construction tool includes a tool body with at least one such cutter attached to the tool body.