Based on https://github.com/bzgeb/AutomaticColliderGeneration

For assets which have colliders included in the FBX or Blender file with a naming convention matching Unreal Engine FBX Static Mesh Pipeline

In all cases colliders should be uniformly scaled.

A Box must be created using a regular rectangular 3D object. You should not move the vertices around or deform it in any way to make it something other than a rectangular prism, only the mesh bounds are respected.

A Capsule must be a cylindrical object capped with hemispheres. It does not need to have many segments (8 is a good number) at all because it is converted into a true capsule for collision. Like boxes, you should not move the individual vertices around.

A Sphere does not need to have many segments (8 is a good number) at all because it is converted into a true sphere for collision. Like boxes, you should not move the individual vertices around.

A Convex object can be any completely closed convex 3D shape. For example, a box can also be a convex object. The diagram below illustrates what is convex and what is not: