From the @param wiki page:
Parameters With Properties
If a parameter is expected to have a particular property, you can document that immediately after the @param tag for that parameter, like so:
/**
* @param userInfo Information about the user.
* @param userInfo.name The name of the user.
* @param userInfo.email The email of the user.
*/
function logIn(userInfo) {
doLogIn(userInfo.name, userInfo.email);
}
There used to be a @config tag which immediately followed the corresponding @param, but it appears to have been deprecated (example here).