How to change the function to limit its action to the id, class or selector

I have a function written in jquery that copies the value of the checkbox to the textarea #msg

$(document).ready(function(){
    $("input:checkbox").click(function() {
        var output = "";
        $("input:checked").each(function() {
            output += $(this).val() + "";
        });
        
        $("#msg").val(output.trim());
    });
});

Clicking any checkbox on side copies of its value to the #msg field How to reduce this effect that only checkboxes in the or a selected div operate in such a manner?

I want this:

<ul>
    <input name="foo2" type="checkbox" value="Hello" id="tel_1">
    <label for="tel_1">Hello</label>
</ul>

To be copied to the #msg textarea and this :

<input name="foo" value="123123123" id="tel_11" type="checkbox">
<label for="tel_11">Alan</label>

Not to be copied. I played with this :

$("input:checkbox").click(function() 

And changed input:checkbox to ul:input:checkbox but I do not want to work.