To judge if a policy can be considered a success or a failure you have to see what goals one wants to achieve thorough that policy.
I am no expert, but through what i observe i see that Modi or Indian foreign policy for that matter is to isolate Pakistan diplomatically, reduce the strategic geographical importance (chahbahar is an example) and maligning us through good old haven of terrorism mantra.
Are we diplomatically isolated, well if you think we could have harnessed some diplomatic goodwill from Bangladesh or Bhutan, then yes otherwise we are not. Our relationship is improving with our neighbors barring India of course. No matter what one say we have much improved relations with Afghans now when compared with Karzai times. We have a much more balanced relationship with US and the EU. Our relations with China are as good as ever. And we have not lost anything in ME and Gulf. So no success on diplomatic front for their policy.
CPEC is an evidence that our geographical importance is well appreciated. We can't say Chahbahar don't have the potential to reduce Gawadar's importance somewhat when it comes to trade in Afghanistan or central asia but the question is just how much. Although we can argue about many things, let's say the distance from the Afghan cities, the capacity of the port itself e.t.c but the main point that many don't give much attention to is that people like to do business in a familiar environment, and Afghans find Pakistan much more familiar than Iran, our second largest ethnic group is their largest, things between us are bound to improve.
And lastly their old mantra is not working. With Zarb e Azb Pakistan has shown its resolve to eliminate terrorism, the world can see that so no one is going to be bothered by this mantra.
So yes Sir, Modi foreign policy on Pakistan is a failure.