There is no single or simple answer. As a general matter, merely having authority to sign contracts and/or checks for an LLC does not make an employee, officer, or even owner liable. However, if the terms of whatever you are gaining signing power for require you to be liable or guaranty the debts--for example, you get power over a line of credit, but as such, you are held accountable on it--that would be enforceable; therefore, you need to check the agreement(s) governing whatever you are gaining authority over, and also the terms of anything you sign, to see if you are thereby making yourself liable.