Consider following option:
@Option
@Documentation("second primitive value")
private boolean boolOption = true;

@Option
@Documentation("suggestable based on boolean value")
@Suggestable(value = "basedOnBoolean", parameters =

)
private String basedOnBoolean;

and action method:
@Suggestions("basedOnBoolean")
public SuggestionValues basedOnBoolean(@Option("bool") final boolean flag)

java.lang.ClassCastException: java.lang.Boolean cannot be cast to java.lang.String
at org.talend.sdk.component.studio.model.parameter.listener.ActionParametersUpdater.propertyChange(ActionParametersUpdater.java:37)
at java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:335)
at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:328)
at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:263)
at org.talend.sdk.component.studio.model.parameter.TaCoKitElementParameter.firePropertyChange(TaCoKitElementParameter.java:85)
at org.talend.sdk.component.studio.model.parameter.TaCoKitElementParameter.setValue(TaCoKitElementParameter.java:189)
at org.talend.sdk.component.studio.model.parameter.CheckElementParameter.setValue(CheckElementParameter.java:50)
at org.talend.designer.core.ui.editor.nodes.Node.setPropertyValue(Node.java:1968)
at org.talend.designer.core.ui.editor.cmd.PropertyChangeCommand.execute(PropertyChangeCommand.java:255)
at org.eclipse.gef.commands.CommandStack.execute(CommandStack.java:199)
at org.talend.designer.core.ui.editor.properties.controllers.AbstractElementPropertySectionController.executeCommand(AbstractElementPropertySectionController.java:1188)
at org.talend.designer.core.ui.editor.properties.controllers.CheckController$1.widgetSelected(CheckController.java:216)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:248)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4454)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1388)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3799)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3409)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1151)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1032)
at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:148)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:636)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:579)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:150)
at org.talend.rcp.intro.Application.start(Application.java:265)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:380)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:235)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:648)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:603)
at org.eclipse.equinox.launcher.Main.run(Main.java:1465)
at org.eclipse.equinox.launcher.Main.main(Main.java:1438)

this is due there is no conversion from native option type to String in Studio integration