Noise wastes the window. A wrong fact in the window does something worse.
Context poisoning
A mistake that gets into the context and stays: a guess stated as fact, an invented function, a wrong summary. Every later turn reads it again and builds on it, so the agent's own earlier words keep arguing for the error.
A correction is one line against all the lines already written in favour of the mistake. So a third correction rarely works, and starting over with what you learned often beats arguing. Memory files can carry the same error into every future session.
Say it to your agent
“Stop. You have been assuming issuedAt is in seconds, and nothing has shown that. Print one real value from the test fixture. Then write what you found to docs/handoff.md, and I will start a new session from that file.”