A long parameter list can indicate that a new structure should be created to wrap the numerous parameters or that the function is doing too many things.
With a maximum number of 4 parameters:
func foo(p1 int, p2 int, p3 int, p4 int, p5 int) { // Noncompliant
// ...
}
func foo(p1 int, p2 int, p3 int, p4 int) {
// ...
}