Alexey, I must report what I've find "Add JBoss Tools Knowledge Base support" behavior complitly strange.
Here I describe 2 situations with my test project:
1) I've added org.jboss.tools.jsf.jsfnature & org.jboss.tools.jst.web.kb.kbnature - manually - after I closed the test project and reopen it - I can navigate with my tags (closed and reopen the project are obligatory steps);
2) when I added via "Add JBoss Tools Knowledge Base support" - I can not navigate to tld files with Ctrl+Left mouse
I'll attach test project here. Could you point what is wrong in my steps?