About [[MediaWiki:Spamdifftool-tool/en]]
Fragment of a discussion from Translating talk:MediaWiki
The documentation is just plain wrong here. It can, should and has been translated already (i.e. the German translation is currently "Spam-Werkzeug", which means "Spam Tool", the French translation ("Outil Spam") also translates back to "Spam Tool" etc.). The proper name of the extension is SpamDiffTool.
For some context: the message in question is the page title — or rather, "HTML title"; that is, the text displayed on your browser's window/tab — of the Special:SpamDiffTool page. It isn't shown anywhere else. You might want to take a look at the extension's infopage on MediaWiki.org for a screenshot of the extension in action and more.