update ci readme

Signed-off-by: Thibault Mange <[email protected]>

cicd-scripts/metrics/README.md

@@ -1,15 +1,18 @@
-# Metrics CI
+# Metrics CI tools
 
-Objective is to ensure that:
-* Metrics needed in dashboards are collected 
-* Rules needed in dashboards are defined
-* No unneeded metric is collected
-* No unneeded rule is defined
-* Metrics matchers are valid in scrapeconfigs => 
-* Query rules are valid => Use promtool check rules
+Collection of simple CI tools and scripts to validate the list of metrics collected for a list of dashboards.
+This helps maintain the list of metrics and rules in sync with the dashboards, and ensure that we don't collect
+more metrics than needed.
 
-E2E tests must ensure that core platform metrics are collected and that dashboards are populated with data (some queries might be invalid)
+More precisely, it helps verifying that:
+* Metrics needed in dashboards are collected, and not more
+* Rules needed in dashboards are defined, and not more
+* Query rules are valid
 
+## Usage
+
+When adding a new list of dashboards in a new directory, make sure that you define the corresponding scrapeConfig and rules.
+Then add a target in the Makefile to run the metrics check for the new dashboards, following the existing examples.
 
 Generate metrics count stats: