Text clarify

runner.py

@@ -1502,7 +1502,7 @@ def run(self):
     parser.add_argument('--docker-prune', action='store_true', help='Prune all unassociated build caches, networks volumes and stopped containers on the system')
     parser.add_argument('--dev-no-metrics', action='store_true', help='Skips loading the metric providers. Runs will be faster, but you will have no metric')
     parser.add_argument('--dev-no-sleeps', action='store_true', help='Removes all sleeps. Resulting measurement data will be skewed.')
-    parser.add_argument('--dev-no-build', action='store_true', help='Checks if a container images are already in the local cache and will then not build it. Also doesn\'t clear the images after a run. Please note that skipping builds only works the second time you make a run.')
+    parser.add_argument('--dev-no-build', action='store_true', help='Checks if a container image is already in the local cache and will then not build it. Also doesn\'t clear the images after a run. Please note that skipping builds only works the second time you make a run since the image has to be built at least initially to work.')
     parser.add_argument('--print-logs', action='store_true', help='Prints the container and process logs to stdout')
 
     args = parser.parse_args()