The JMX 1.2 specification document is supposed to clarify, per the Maintenance Review change list, that getters and setters in a Standard MBean cannot be invoked through MBeanServer.invoke. But the text to this effect erroneously appears in the section about Dynamic MBeans (bottom of p42). It should obviously be in the section about Standard MBeans, e.g. on p40.
Also, this text mentions the property "jmx.invoke.getters". Since it appears in the spec, one might conclude that an implementation is required to respect this property. But that's not what was stated during the Maintenance Review and it's not what was intended. Rather, this property is a feature of the Reference Implementation to ease the transition for code that may have incorrectly relied on being able to invoke getters before. So it should appear in the Release Notes of the RI, not in the spec. Having such a property is a violation of compatibility rules so it will be phased out in the future.