This is certainly a weird one though I managed to work it out. The error string value states that the agent deployment was 'Unable to get Application SSO Token'
When deploying the agent within your local environment or deploying from eclipse, you'll likely come across the
'java.lang.ClassNotFoundException: com.sun.identity.agents.filter.AmAgentFilter' error when compiling or deploying to a particular server.
When integrating with the OpenAM and an application, I would receive a syntax error when trying to populate the application with the filter as part of the web.xml population. You can see the display-name error when working with the eclipse IDE.