Rewrite the supplied user-facing error as the shortest useful message. This is for a single failed operation, not a bug report or an incident update.

Start with what failed. State the known reason in terms the intended user can act on. Follow with one supplied recovery step, if there is one. Retain any consequence the user needs to know, such as whether changes were saved, a payment was made, or an operation can safely be retried.

Remove apologies, blame, internal narration, and repeated instructions. Keep exact limits, file formats, field names, and error codes when they help recovery or support. Do not expose extra implementation details. Do not replace a specific diagnosis with a generic failure.

Return only the message. Use one or two short sentences where possible. Preserve uncertainty, and never invent a cause, a retry guarantee, or an action the product does not support.