As a Buyer, the information you receive about a property will come from a variety of sources. Among these are public records, a home inspection report, and the Seller's Property Disclosure Statement, in most cases. As a Seller, the information you provide needs to come from you.
The Good. The Seller's Disclosures Statement says "Sellers are obligated by law to disclose all known material (important) facts about the Property to the Buyer." It is a 7-page document that is one-part checklist, one-part fill in the blanks. Categories covered include Property and Ownership, Building and Safety, Utilities, Environmental Information, and Sewer/Wastewater Treatment. There's also a place for additional explanations and comments. It's pretty extensive and covers items that may not apply to every property.
By signing it, the Seller is certifying they have answered the questions honestly and completely, to the best of their knowledge, as of the date signed. Should the Seller's knowledge change between signing and the closing, they are required to revise it. And this happens. Perhaps they forgot something or received a copy of a Home Inspection from a Buyer who canceled. Anything on a report they did not know about - but now do - must be added to the disclosure statement.
The Bad. Things can get missed, forgotten, or overlooked. It can happen, and it is the most compelling reason there is to get a home inspection. A home inspection could reveal a condition the Seller did not disclose - for whatever reason. When the inspection reveals an issue, it is almost always because the Seller was unaware of it. Regardless, the Buyer only learned of it because of the Inspection Report.
Contrary to popular belief, Sellers are "not obligated to disclose if the property has been (1) the site of a natural death, suicide, homicide, or any other crime classified as a felony (2) owned or occupied by a person exposed to HIV, diagnosed as having AIDS, or any other disease not known to be transmitted through common occupancy of real estate, or (3) located in the vicinity of a sex offender." If they know, they cannot lie but are only obligated to say "by law, I am not required to disclose that information." As a Buyer, if it is important to you, do your research during the inspection period.
The Unknown. Disclosures only cover conditions of which the Seller has personal knowledge. If a property is sold by a Bank, Trust, or through a Probate Sale, the entity selling the home is likely to have no first-hand knowledge of conditions that may exist. This situation is common, and the listing will specify that the Buyer must "waive the SPDS." Unfortunately, this is also a common ask with property flippers who SHOULD be required to complete disclosures, as even though they have never occupied the property, as are fully aware of the work that has been done, and have first-hand information about utilities and property conditions. If you are looking at a property where you are required to waive the disclosures, you need to ask WHY. It could be a logical reason, or it could be a red flag.