Is it possible to set a hint-text for js-object outputs?

This can be done using the setoutletassist function.
Example from the docs:
function describe_it(num)
{
assist("this is outlet number",num);
}
// global code to set it up
setoutletassist(-1,describe_it);

To set each outlet individually, you could simply write more than one 'describe_it' functions, and map each one to a specific outlet number (rather than using -1 as the outlet number from the docs example)

More info can be found at the bottom of this page: https://cycling74.com/docs/max6/dynamic/c74_docs.html#jsglobal