Sentence examples for are not foolproof from inspiring English sources

But they are not foolproof.

These treaties are not foolproof.

As such, they are not foolproof representations.

The tests, however, are not foolproof.

Even the best tools are not foolproof.

But limit orders are not foolproof.

Systems aren't foolproof.

IED detectors aren't foolproof.

But their defense measures aren't foolproof.

But it is not foolproof.

But it's not foolproof.