Side effects

Run something against the value without changing it.

Inspect

Option<T> Inspect(Action<T> action)

Runs an action against the value when the option is Some, and hands the option back unchanged so the chain continues. Logging is the usual reason.

Option<string> maybeName = Option.Some("Geladon");
maybeName.Inspect(name => Console.WriteLine(name.Length));

On a None: the action never runs, and the None comes back.

Reach for Map instead if you want to change the value.

There is no InspectNone. Use Match when both branches need to do something.

Why not just ToString it?

ToString() never shows the wrapped value. You get the state and nothing else:

Option.Some("Vex'ahlia").ToString() // "Some { IsSome = True, IsNone = False }"
Option.None<string>().ToString()    // "None { IsSome = False, IsNone = True }"

Option<T> is a record and Some<T> keeps its value in a private property, so the compiler-generated ToString() has nothing to print. Interpolating an option into a log message tells you whether a value was there, never what it was. That is what Inspect is for.