There are seven instances when a tester need to knock to Project Manager for certain requirements or help from him without which his role as a tester cannot move further. Any lack in those assistance to tester will certainly mean lack in delivery of right product/ bug free product.
For isntance a tester certainly require business requirements document to understand what initally has been asked by business owner to build in the software viz a viz what actually the product has been built by development team.
Around three years back I wrote a post relevant to the same subject I have discucced above primarily talking about the crux of the requirements by a tester to justify his work related to a software project. The article was titled as ”Knock! Knock! – It IS Tester Here!”