How can this sentence be correct?

I read the following sentence in a book and could not in any way justify the correctness of the sentence. Please help:

Most states impose limitations on the authority of the legislature to borrow money, limitations intended to protect taxpayers and the credit of the state government.

Why could we not just write:

Most states impose limitations on the authority of the legislature to borrow money, to protect taxpayers and the credit of the state government.

Or,

Most states impose limitations, which are intended to protect taxpayers and the credit of the state government, on the authority of the legislature to borrow money.

There’s usually more than one way to express anything. The sentence you quote is certainly grammatical. The writer has repeated and expanded limitations presumably in order to emphasise them and their intended purpose.

The sentence looks OK to me. I would regard everything after the comma, "limitations ... government", as being in apposition with the preceding noun phrase, "limitations ... money".