Ambiguity isn't a unary function. It doesn't make sense to say "this sentence is ambiguous" without some context:

• What's the social context in which the sentence is spoken? "I love you" from a child to a parent almost certainly doesn't mean the same thing as "I love you" from an adult to a lover. This isn't ambiguity; it's context dependence.
• What are the likely (mis)interpretations? How distant are they from each other in meaning-space? Do those differences matter? "Go to the library and get me Moby-Dick" might leave the hearer unclear as to which library is meant (the college library? the public library? the main branch of the public library? the room in the house with lots of bookcases?) ... but maybe the speaker doesn't care about the difference — they just want their damn whale book.
• Is the sentence intended to nail down one specific meaning when some hearers would prefer a different one? For some purposes, such as laws and rules, people want a very clear idea of what's being forbidden, even in a context where people have strong disagreements about what should be forbidden. See for instance the U.S. jurisprudence notions of the vagueness doctrine and the "chilling effect".
• For that matter, what level of language skill does the speaker/writer expect from the hearer/reader, and how much care is the hearer/reader expected to apply? Some grammatical forms are harder to parse. There are a number of example sentences where introducing a comma or pause in the wrong place can completely change the sense of the sentence.

"Woman: Without her, man is nothing" / "Woman, without her man, is nothing".
"I helped my Uncle Jack off a horse" / "I helped my uncle jack off a horse".
"Unless a player has Book Burning deal six damage to him or her ..." / "Unless a player has Book Burning, deal six damage to him or her ..."