Yeah, we define laws but laws also define matter.
If everything is bound by a law and we say "this is how it works" that doesn't mean it works that way because of the matter it means that matter works that way because of the law. All we've really done essentially is discover the law and that's what science is about. Putting the pieces of the puzzle together.
eg( Isaac saw that everything fell down. It doesn't fall down because he noted that it did. It always did he just noticed it. Thus, he came to the conclusion about gravity. All matter is bound by gravity, gravity exists because of matter. Therefore, the law isn't that gravity exists, but that matter exists. But why would gravity exist? It must be to create a balance. Therefore gravity exists because matter exists and matter which is made up of energy exists because energy exists.)
These laws whether or not we discover them exist. Identifying them is as you say our way of explaining how it works. But, we do not make them work in such a way. This isn't chemistry law with exceptions. There are no exceptions.