Public ReadOnly Property Description As String

public string Description {get;}

<esri:Map Name="Map1" Height="400" Width="400" ">
  <!-- Description Property (Read Only). -->
  <esri:ArcGISImageServiceLayer 
        Url="http://sampleserver3.arcgisonline.com/ArcGIS/rest/services/Portland/CascadeLandsat/ImageServer"/>
</esri:Map>
<TextBlock Name="TextBlock_Description" Height="23" Width="248" 
           Text="{Binding ElementName=Map1, Path=Layers[0].Description}"/>

private void MainPage_Loaded(object sender, System.Windows.RoutedEventArgs e)
{
  
  // The Map1 object (a Map object) was defined previously in XAML.
  
  // Create an ArcGISImageServiceLayer.
  ESRI.ArcGIS.Client.ArcGISImageServiceLayer myArcGISImageServiceLayer = new ESRI.ArcGIS.Client.ArcGISImageServiceLayer();
  myArcGISImageServiceLayer.Url = "http://sampleserver3.arcgisonline.com/ArcGIS/rest/services/Portland/CascadeLandsat/ImageServer";
            
  // Create an Event Handler.
  myArcGISImageServiceLayer.Initialized += new System.EventHandler<EventArgs>(ArcGISImageServiceLayer_Intialized);
                 
  // Add the ArcGISImageServiceLayer to the LayerCollection of the Map.
  Map1.Layers.Add(myArcGISImageServiceLayer);
                 
}
                 
private void ArcGISImageServiceLayer_Intialized(object sender, EventArgs e)
{
                 
  // The Map1 object (a Map object) and TextBlock_Description (a TextBlock object) were defined previously in XAML.
                 
  // Access a specific ArcGISImageServiceLayer.
  ESRI.ArcGIS.Client.ArcGISImageServiceLayer myArcGISImageServiceLayer = (ESRI.ArcGIS.Client.ArcGISImageServiceLayer)Map1.Layers[0];
  
  // Description Property (Read Only).
  TextBlock_Description.Text = myArcGISImageServiceLayer.Description;
                 
}

Private Sub MainPage_Loaded(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles Me.Loaded
                 
  ' The Map1 object (a Map object) was defined previously in XAML.
                 
  ' Create an ArcGISImageServiceLayer.
  Dim myArcGISImageServiceLayer As New ESRI.ArcGIS.Client.ArcGISImageServiceLayer
  myArcGISImageServiceLayer.Url = "http://sampleserver3.arcgisonline.com/ArcGIS/rest/services/Portland/CascadeLandsat/ImageServer"
                 
  ' Create an Event Handler.
  AddHandler myArcGISImageServiceLayer.Initialized, AddressOf ArcGISImageServiceLayer_Intialized
                 
  ' Add the ArcGISImageServiceLayer to the LayerCollection of the Map.
  Map1.Layers.Add(myArcGISImageServiceLayer)
                 
End Sub
                 
Private Sub ArcGISImageServiceLayer_Intialized(ByVal sender As Object, ByVal e As EventArgs)
                 
  ' The Map1 object (a Map object) and TextBlock_Description (a TextBlock object) were defined previously in XAML.
                 
  ' Access a specific ArcGISImageServiceLayer.
  Dim myArcGISImageServiceLayer As ESRI.ArcGIS.Client.ArcGISImageServiceLayer = Map1.Layers.Item(0)
                 
  ' Description Property (Read Only).
  TextBlock_Description.Text = myArcGISImageServiceLayer.Description
                 
End Sub