Good question. If you are ever in doubt, disclose and sleep much better every night in the future!
The local board of realtors typically has a disclosure form. Sometimes they can be confusing so when completing, take your time and consult the agent you choose to work with. He/she can explain what each question is after.
When completing your property disclosure, write anything you know about the past leak(s), what work was done to repair(always including any invoices which may show possible warranty info), when the work was done, and what area of the home was repaired.
If you tell the potential buyer everything you know, you are better off. The buyer usually has their own agent representing them so they typically pay for an independent inspection to check and verify the statements you have made.
Again, the agent you choose should have the experience and expertise to assist you with the disclosure.
The best of luck!
The primary principle is that of "material fact". (This is NOT legal advice. Consult an attorney for legal advice).
If a buyer knew about a certain fact, could it affect their decision to make an offer on the property?
There is only one rule about disclosures : Disclose, disclose, disclose.
A good Realtor can help you navigate these areas. A NAR survey at one time cited that 70% of lawsuits are filed by buyers. One of a Realtor's jobs is to keep you out of court.
Bear in mind also that once you are aware of something, you need to disclose it.
You can discuss the "As Is" addendum with your agent.