I did a lot of research on internet regarding the connotation of word shrewd. It can have negative as well as positive connotation.It depends on the context of the passage. For instance,
A shrewd real estate agent
A shrewd business man
Another usage of shrewd is for decisions, policies, judgements etc. Well, I was looking for this particular usage on dictionary and found this. Second usage has confused me a bit as it is mentioned that shrewd activities are marked as artful and cunning practices. Now the word cunning has purely negative connotation. So I want to know how do native speakers use this word? Specially I am confused about its usage with activities. For Instance - a shrewd policy or a shrewd decision. An example for negative usage of shrewd could be this sentence
The union was known for its shrewd negotiating tactics. (calculating, underhanded)
On Twitter, he said it was a “brutal conspiracy and a shrewd scheme” that allowed Mr. Modi’s “suit-boot friends to convert their black money into white”.