diff --git a/jenkins/client/job/validate.yml b/jenkins/client/job/validate.yml
index 0f0bbf8..bde6f77 100644
--- a/jenkins/client/job/validate.yml
+++ b/jenkins/client/job/validate.yml
@@ -501,6 +501,7 @@
                   SHAKER_SERVER_ENDPOINT: '10.13.0.15:5999'
                   SHAKER_SCENARIOS: 'scenarios/essential'
                   SKIP_LIST: ''
+                  MATRIX: ''
                   image_builder:
                   #  - SHAKER_FLAVOR_DISK=4
                   #  - SHAKER_FLAVOR_RAM=512
@@ -523,6 +524,11 @@
                     scenarios/additional/cross_az
                     scenarios/additional/external
                     scenarios/additional/qos
+                  "MATRIX" - Set the matrix of extra parameters for the scenario. The value is specified in JSON format.
+                  To override a scenario duration one may provide "{time: 10}", or to override list of hosts:
+                  "{host:[ping.online.net, iperf.eenet.ee]}". When several parameters are overridden all combinations are
+                  tested. It is a required field for some of external-category scenarios when the host name with iperf3
+                  server needs to be provided as a command-line parameter, e.g. "{host: 10.13.100.4}".
                   "SKIP_LIST" - Comma-separated list of Shaker scenarios to skip, directories or files inside scenarios/
                   of cvp-shaker, e.g. "dense_l2.yaml,full_l2.yaml,l3"
                   "image_builder" - shaker-image-builder env variables