The SARIF Multitool is a .NET Core command line tool that performs a variety of operations on SARIF files. It requires the .NET Core 2.1 Runtime.
With the runtime installed, install the tool as follows:
dotnet tool install --global Sarif.Multitool
This add a command named sarif to your execution path. In a new command window, you can now issue sarif commands, such as this one that validates a SARIF file against a set of built-in validation rules:
sarif validate MyFile.sarif --output MyFile-validation.sarif