Update call-metrics-log-schema.md

Author: amagginetti

articles/communication-services/concepts/analytics/logs/call-metrics-log-schema.md

@@ -57,28 +57,17 @@ This table describes each property.
 
 | Property                     | Description                                                                                                                |
 |----------------------------|----------------------------------------------------------------------------------------------------------------------------|
-| `reliability/api/CreateView/Local` | TODO | 
-| `reliability/api/Join`             | TODO                |
-| `reliability/api/StartVideo` | TODO |
-| `reliability/api/AcceptIncomingCall` | TODO |
-| `reliability/api/CreateView/Remote` | todo |
-| `reliability/api/StopVideo` | todo |
-| `reliability/api/CallAgentInit` | todo |
-| `reliability/api/StartCall` | todo | 
-| `reliability/api/Drop` | todo |
-
-
-
-
-- reliability/api/CreateView/Local
-- reliability/api/Join
-- reliability/api/StartVideo
-- reliability/api/AcceptIncomingCall
-- reliability/api/CreateView/Remote
-- reliability/api/StopVideo
-- reliability/api/CallAgentInit
-- reliability/api/StartCall 
-- reliability/api/Drop
+| `reliability/api/CreateView/Local` | Measures the reliability of the calling SDK `CreatView/Local` API which renders local video streams. This API is required for user's to see their local video stream. | 
+| `reliability/api/Join`             | Measures the reliability of the calling SDK `Join` API. When this API succeeds, a user's client is admitted to an existing call or meeting.                 |
+| `reliability/api/StartVideo` | Measures the reliability of the calling SDK `StartVideo` API which begins streaming video from the calling client to remote participants. When this API succeeds a user's client successfully sends video. |
+| `reliability/api/AcceptIncomingCall` | Measures the reliability of the calling SDK `AcceptIncomingCall` API which indicates the client successfully accepted and connected to an incoming call. |
+| `reliability/api/CreateView/Remote` | Measures the reliability of the calling SDK `CreateView/Remote` API which indicates the client successfully renders incoming video from a remote participant. |
+| `reliability/api/StopVideo` | Measures the reliability of the calling SDK `StopVideo` API which indicates the calling SDK successfully stopped streaming video to remote participants. |
+| `reliability/api/CallAgentInit` | Measures the reliability of the calling SDK `CallAgentInit` API which indicates the calling SDK successfully created the `CallAgent` object. If this fails, the reliability/api/Join or reliability/api/StartCall APIs can not be triggered. |
+| `reliability/api/StartCall` | Measures the reliability of the calling SDK `StartCall` API which indicates the calling SDK succseffuly initiated a new call.  | 
+| `reliability/api/Drop` | Measures the reliability of individual call legs by identifying which call legs were dropped unexpectedly after they successfully connected to a call. Focuses on participants call legs that successfully connected to a call and checks if the call legs were later dropped due to specific error codes.  |
+
+
 
 ### User Facing Diagnostics (UFD) metrics