Purpose of the pen tool not clear from the UI

[skadge]

The pen tool:

appears in the tool menu, next to the mirroring tool.

While the mirroring tool's purpose is clear, I'm not sure what it the intended use of the pen tool.

[JamesMcCrae]

It allows for iterative placement of each vertex/control point of the spline (as opposed to the default "sketch" mode which attempts to best-fit a spline to a sketched input polyline).

When in use, there are contextual instructions shown in the UI, like the following:

Any specific suggestions on how this could be improved?