The parenthetical here is a little confusing to me, but I'm not sure I quite follow what you're trying to say well enough to offer alternative suggestions.  Some questions:

 * Is there a distinction between the "client" and "client library" mentioned in the same sentence here?
 * Why/when would this disconnection happen, and does that matter?
 * Would "the client library should *only* attempt to reconnect if that instance is discovered…" make this clearer?