To be honest of the three party main party leaders Mr. Singh seems to have expressed the most detailed policy info, certain in their leadership campaigns.  His policies might have been a bit light on details, but at least he HAD policies and had the described at a high level.

I'll grant Andrew Scheer a bit more time to pass judgement, but in his leadership campaign he was very light on policy and he hasn't exactly outlined much more since becoming leader.

As for Justin Trudeau, in his leadership campaign the grand sum total of all his policies, from immigration to economics to social issues was just a single sentence: "Hello, my name is Justin Trudeau".  That was it.  Since becoming leader of the party and now PM he hasn't brought out much more in the way of policy.