If a new slave is defined that contains parentheses in its name, the JNLP agent launch string generated by Jenkins will not work as given, and the shell will report an error if the user attempts to use the launch string as-is. Parentheses are shell special characters.

The generated JNLP agent launch string URL should use full URL ASCII character encoding for whatever shell-special characters are permitted in a Jenkins slave name.

$ java -jar /Users/builder/jenkins/slave.jar -jnlpUrl https://myjenkins:8443/computer/SST%20Mac%20OSX%2010.11%20Xcode%207%20(2)/slave-agent.jnlp

should be

$ java -jar /Users/builder/jenkins/slave.jar -jnlpUrl https://myjenkins:8443/computer/SST%20Mac%20OSX%2010.11%20Xcode%207%20%282%29slave-agent.jnlp