diff --git a/scenarios/run_scenarios.md b/scenarios/run_scenarios.md
index c7b4aee..9954360 100644
--- a/scenarios/run_scenarios.md
+++ b/scenarios/run_scenarios.md
@@ -20,7 +20,7 @@ Scenarios `grpc.js`, `local.js`, `http.js` and `s3.js` support the following opt
   * `SELECTION_SIZE` - size of batch to select for deletion (default: 1000).
   * `PAYLOAD_TYPE` - type of an object payload ("random" or "text", default: "random").
   * `STREAMING` - if set, the payload is generated on the fly and is not read into memory fully.
-  * `METRIC_TAGS` - `instance` tag value.
+  * `METRIC_TAGS` - custom metrics tags (format `tag1:value1;tag2:value2`).
 
 Additionally, the profiling extension can be enabled to generate CPU and memory profiles which can be inspected with `go tool pprof file.prof`:
 ```shell