No, but ...
Real estate contracts almost always contain “entire agreement” clauses that mean only those clauses in the contract are part of the contract.
However, it appears your agent (note the “your”) misrepresented the property by stating (in writing) that certain items would be repaired.
If that induced the buyer to enter the contract, then they have the right to rescind it - that is, walk away from the deal, you keep the house, they keep their money. Or, affirm it and sue for damages. Recent case law from the UK has found that entire agreement clauses are not always a shield against misrepresentation.
As far as the buyer is concerned, there is no difference between you and your agent: if your agent said it, legally, you said it. Between you and your agent, you are responsible if the agent was acting within the scope of their agency even if they made reasonable decisions that you don’t or wouldn’t agree with. Agreeing to fix items on a property to secure a sale is probably within the scope of the agency. It’s annoying and unprofessional that they didn’t tell you about it but it’s probably not a breach of their duty to you.