There are various options you can employ to reduce the amount of memory an agent uses.
Limit Plug-in Loading
The best way to reduce an agent's footprint is to configure it to load only the plug-ins for the resource types you want to monitor. See Configuring Plug-in Loading.
Reduce Java Heap
To reduce the Java heap size that an agent allocates to itself on startup, add the
agent.javaOpts property to the agent's agent.properties file. This property does not exist in the default agent.properties file.
You can reduce the heap from 128m to 64m.
Delete JavaDocs File
In an environment in which every MB is critical, you can delete the agent's javadocs folder, agent-4.x.x/bundles/agent-4.x.x-yyyy/pdk/javadoc;. Note that this action only reduces the agent footprint by (approximately) 70 MB.