Whether it is possible to push descriptions of the same functions into user-defined functions? Wouldn't that be bad manners?

Question

PHP

I have the following question, if I stuff a description of the very same function into each of my user-defined functions, will it not be some kind of bad form in programming? Or not? What do you think?
Here is an example:
If I forget, for example, what this function does, I simply pass it as a string parameter, such a secret code - "}{eLpEr#", and it gives me a hint:
"The myBasket() function does not accept anything , but returns an array."
If nothing is conveyed, it will simply fulfill its purpose.
PHP example.
function myBasket($data=""){
if($data == "}{eLpEr#")
echo 'MyBasket() does not accept anything, but returns an array.';
else{
... the code that executes the myBasket() function;
}

Answer 1

And what is it for then?
https://ru.wikipedia.org/wiki/PHPDoc

Answer 2

To do this, there are comments and PHP code commenting standards that many IDEs support. And yes, that would be bad manners.