If it looks like a bean, and it's in a bed where you're growing beans, then ....

These beans look desperately old and past their prime. That would certainly account for stringiness and toughness in a regular green bean. Can I assume these are supposed to be regular green beans? What variety are you working with?

I believe high temperatures may also make beans get stringy.

You can eat them. Chop up the green ones and add to soups or casseroles.

Hard to say, but it could be an old bean, or based upon the appearance of the dry pod, it could be an adzuki. Adzuki plants resemble bush beans, but they generally have prominent yellow flowers.

Can you show the plant they're growing on? And tell us the size of those beans?

Thanks everyone. Here are some more pics... the leaves come in clusters of three, so as the beans..