Children are deemed to be property of their parents and don't actually have a lot of rights. On the flip side of that coin they also don't have a lot of responsibility. It is the parent that will get in trouble if the child does something wrong or illegal. Therefore, what the definition of 'children's rights' might be is left to judgment by people who use the term. It is a nice sounding term, but the meaning is very ambiguous and needs to be defined.
I am not saying that children are not protected on a variety of levels,but they do get lost in translation. They need step up their game as things are changing, children are evolving much faster than before. The world is evolving as well, they can't be considered children much longer, but they still need more rights.
No, children's rights are not a slogan in need of a definition, because a slogan never protected anyone. A slogan is a nice saying that is not going to keep a child safe. What we really need are tough laws. We need to hold people who abuse and neglect children accountable.
I believe it is important to protect children from injustices but I do not think those protections should be equated to children's rights. Therefore, there is no reason to further define what children's rights are. If children acquire a lot of rights through law then the parents end up losing power and that limits their ability to raise their children. While it is good to say children shouldn't be used for labor, and one may associate that with children's rights. It is equally bad to say that children have absolute freedom, because if that is the case, then parents break that right on a daily basis.