[src/cli] README files updated to clarify a Commissioner is used for …

…changing datasets.

src/cli/README_COMMISSIONER.md

@@ -1,5 +1,12 @@
 # OpenThread CLI - Commissioner
 
+## Overview
+
+The Commissioner is an entity that can add new Thread devices securely to a Thread network. It also can manage a Thread 
+network by changing network configuration parameters ([Operational Datasets](README_DATASET.md)) or sending specific 
+management/diagnostic commands to selected Thread devices. Before a Commissioner can do its tasks, it has to petition to 
+the Leader to get permission to become the Commissioner. 
+
 ## Quick Start
 
 See [README_COMMISSIONING.md](README_COMMISSIONING.md).

src/cli/README_COMMISSIONING.md

@@ -1,10 +1,15 @@
 # OpenThread CLI - Commissioning
 
+## Overview
+
+Commissioning is the process of adding a new Thread device, called the Joiner, to a Thread network. This process is done 
+under guidance of a [Commissioner](README_COMMISSIONER.md).
+
 ## Quick Start
 
 ### Form Network
 
-Form a network with the device that has Commissioner support.
+Form a network with the Thread device that has Commissioner support.
 
 1. Generate and view new network configuration.
 

src/cli/README_DATASET.md

@@ -4,6 +4,18 @@
 
 Thread network configuration parameters are managed using Active and Pending Operational Dataset objects.
 
+### WARNING - Restrictions for production use!
+
+The CLI commands to write/change the Active and Pending Operational Datasets may allow setting invalid parameters, or 
+invalid combinations of parameters, for testing purposes. These CLI commands can only be used:
+
+- To configure network parameters for the first device in a newly created Thread network.
+- For testing (not applicable to production devices).
+
+In production Thread networks, the correct method to write/change Operational Datasets is via a [Commissioner](README_COMMISSIONER.md) 
+that performs [commissioning](README_COMMISSIONING.md). Production devices that are not an active Commissioner and are part 
+of a Thread network MUST NOT modify the Operational Datasets in any way. 
+
 ### Active Operational Dataset
 
 The Active Operational Dataset includes parameters that are currently in use across an entire Thread network. The Active Operational Dataset contains: