They are supposed to tell the truth if you ask the right questions. However, they are not required to volunteer information. If they have anything to hide, you will not hear about it. And, since the information is communicated to you in sales pitches, you have no written record of what they said so it is your word against theirs.
You don't know unless you conduct thorough background checks that confirm the accuracy of advisor claims for their expertise, ethics, and business practices.
Advisors do not make money unless they gain control of your assets. They omit information, for example lack of experience, because you will not buy what they are selling. They misrepresent information to make them sound more knowledgeable than they really are because they know that is what you want to hear.
You should focus on criteria that impact advisor knowledge: education, certifications, designations, accreditations, and memberships in associations that have significant continuing education requirements.
You should review their compliance records at FINRA.org and talk to your State's Securities and Insurance Commissioners. You should also limit your selection to advisors who are Registered Investment Advisors or Investment Advisor Representatives, acknowledged fiduciaries, and compensated with fees.
Advisors use personalities, brand names, and sales skills to convince you they are competent, ethical professionals. None of these sales tactics have anything to do with their competence and integrity.