ScriptDoc is the tool that Aptana uses to generate the content for Code Assist from JavaScript code. (To learn more about Code Assist, see About Code Assist.) ScriptDoc automatically scans all of the projects in your project for ScriptDoc documentation blocks and displays the Code Assist bubbles when you use the classes and functions that you have documented.
You do not need to run any separate tool or compile anything for Code Assist to work. It should work as soon as you document a function and call that function elsewhere in your code for code within a file. For code in separate files, simply set up a Code Assist profile (See Displaying the References View for help) for your project.
To learn how to document your code so that Code Assist works, see Documenting your code using ScriptDoc.