add documentation for verify-cli-conventions

Author: pravarag

contributors/devel/sig-testing/verify-tests.md

@@ -135,11 +135,31 @@ script:
 
 ## `verify-boilerplate`
 
-This script checks for the boilerplate header for all the files,
-whether the header is correct or wrong. The script collects all the
-file names generated by `hack/boilerplate/boilerplate.py` script and
-stores them into a list called `files_need_boilerplate`.
+This script checks for the license headers for all the files, whether
+the header is correct or wrong. The purpose of boilerplate headers is
+to identify license headers. The script collects all the file names
+generated by `hack/boilerplate/boilerplate.py` script and stores them
+into a list called `files_need_boilerplate`.
 
 Once we collect all the file names, we run a check to identify the
 files with wrong header. This check will only run if the file exists
 in the list mentioned above.
+
+
+## `verify-cli-conventions`
+
+This script checks whether the description format of `help` message of
+kubectl command is valid or not. This check is done for all the
+`kubectl` sub-commands as well. The script first checks whether the go
+command is available or not in the ${PATH}. And then the binary
+`cmd/clicheck` is checked if it exists or not in the well-known output
+locations. It runs command checks on all the kubectl commands or subcommands like,
+
+```bash
+kubectl version
+kubectl uncordon
+kubectl wait
+kubectl top node
+```
+And if the output looks good i.e. CLI follows all tested conventions the test passes.
+