The definition of software development methods encompasses the definition of syntax and static semantics of formal languages. These languages determine documents to be produced during the application of a method. Developers demand language-based tools that provide document production support, check syntax and static semantics of documents and thus implement methods. Method integration must determine inter-document consistency constraints between documents produced in the various tasks. Tools must, therefore, be integrated to implement the required method integration and check or even preserve inter-document consistency. The focus of this paper is on the specification of such integrated tools and outlines the main concepts of the object-oriented tool specification language GTSL.