Bone info is a small utility from Chuggnut for 3ds Max that operates inside the skin modifier. After you select a set of vertices and press its button, the tool gathers the bone assignments and weights tied to each vert, giving you a direct read on how the selection is bound.
The developer positions it as handy for fixing blending problems, where per-vertex weight data helps you see what's driving a deformation. Alongside the assignments and weights, Bone info also reports whether the vertex weights are normalized, so that state is visible without a manual check.
Listed on scriptspot at version 2.3.5, Bone info keeps its scope on reading per-vertex skin data. You can find it through the developer's page at chuggnut.com for download and current details.