In this case wirecut or extrude and subtract would do it. However, I have edges of various shapes that need a gear edge cut into them. I have found several gear solutions to straight edges but none for curves.
Get the length of the target curve and create a straight line of that length along the profile.
Use _Flow with the straight line as the baseline and the curve as the target.
(experiment with the _Flow options to see what suits your purpose best - a lot depends on what distortion you can accept.
The help file entry on Flow along Curve will help with your choice of options.
The edges get more complex for this problem. How might I approach this:
I have a truncated cone (in blue) The upper truncation is curved. Using FLOW as suggested I have created a scalloped edge at the top (you can ignored the inner shape).
Now I need to create a scallop shape that lies along the cone with the teeth going down.
The shape I need to create is then a cone with the bottom edge scalloped.
In in the real word, the outward scallop and the downward scallop would be an L-Bar wrapped around the cone with teeth cut into it.
(I also need to create similar scalloped L at the bottom.)