class not found exception in MR job invoked by toolttasklet

[timodavid]

I always get following error when I run tool-tasklet.

java.lang.RuntimeException: java.lang.ClassNotFoundException: org.apache.hadoop.examples.WordCount$TokenizerMapp er
at org.apache.hadoop.conf.Configuration.getClass(Conf iguration.java:1081)
at org.apache.hadoop.mapreduce.JobContext.getMapperCl ass(JobContext.java:212)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapT ask.java:609)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java: 325)
at org.apache.hadoop.mapred.Child$4.run(Child.java:27 0)
at java.security.AccessController.doPrivileged(Native Method)

My configuration is as follows.
<hdp:tool-tasklet id="wc-tasklet" scope="step" tool-class="com.abc.WordCountToolRunner" libs="cp/hadoop-examples-0.20.204.0.jar" jar="cp/tool.jar">
<hdp:arg value="#{jobParameters['inputFile']}"/>
<hdp:arg value="#{jobParameters['outputFile']}"/>
property=value
</hdp:tool-tasklet>

I am wondering how we can add 3 rd party libraries to classpath of MR job from tool-tasklet.