Some of the examples in the Scripting Index have lots of details and useful comments:

When a user submits a function via Add custom Function(), such comments are automatically removed:

What do I have to do to see the comments?
Add Custom Functions(
New Custom Function(
"test",
"f",
Function( {}, Print( "hello world" )
),
<<Description( "test function" ),
<<Example(
Expr(
x=3;
// here I want to add a comment which will be displayed in the scripting index
f()
)
)
)
);