--- a/mobile/android/docs/uitelemetry.rst
+++ b/mobile/android/docs/uitelemetry.rst
@@ -61,17 +61,17 @@ Events capture key occurrences. They sho
 
 ``action``
   The name of the event. Should be brief and lowercase. If needed, you can make use of namespacing with a '``.``' separator. Example event names: ``panel.switch``, ``panel.enable``, ``panel.disable``, ``panel.install``.
 
 ``method`` (Optional)
   Used for user actions that can be performed in many ways. This field specifies the method by which the action was performed. For example, users can add an item to their reading list either by long-tapping the reader icon in the address bar, or from within reader mode. We would use the same event name for both user actions but specify two methods: ``addressbar`` and ``readermode``.
 
 ``extras`` (Optional)
-  For extra information that may be useful in understanding the event. Make an effort to keep this brief.
+  For extra information that may be useful in understanding the event (such as a short string, a json blob, etc).
 
 ``timestamp`` (Optional)
   The time at which the event occurred. If not specified, this field defaults to the current value of the realtime clock.
 
 Versioning
 ==========
 
 As a we improve on our Telemetry methods, it is foreseeable that our probes will change over time. Different versions of a probe could carry different data or have different interpretations on the server-side. To make it easier for the server to handle these changes, you should add version numbers to your event and session names. An example of a versioned session is ``homepanel.1``; this is version 1 of the ``homepanel`` session. This approach should also be applied to event names, an example being: ``panel.enable.1`` and ``panel.enable.2``.