Osric is a classic yes man.
If Hamlet wanted an honest answer to this question, he could not be sure with a question like this. If Osric can answer “yes” he will.
“Are they all the same length? “ “Yes!” “Are these swords all different lengths?” “Yes!”
You’d have to ask “What are the lengths of these swords?” to get something besides yes.
One of things I learned from teaching is what kinds of questions are fruitful and which are dead ends. Questions that lead to Yes or No are not very useful in that, aside from motivations to agree or disagree with the asker, they tend to stop the conversation.
“Is Osric complicit in this plot?” is not as productive a question as “How might Osric be complicit in this plot?”
Then you get some goods. And then you can ask its opposite, “In what ways might Osric be innocent?”
The Hamlet Project 