The thing with a messaging "hello" is it doesn't provide much of that information. You're only able to evaluate the time commitment and urgency by having the c

The thing with a messaging "hello" is it doesn't provide much of that information. You're only able to evaluate the time commitment and urgency by having the content of the request - a "Hello" ping on instant messenger is an attention stealer but it prevents the reader from being able to triage. It commits them to paying attention and waiting for at least part of a conversation that they may or may not have time for.