diff --git a/content/docs/command-reference/exp/run.md b/content/docs/command-reference/exp/run.md
index de2277c076..d09450924e 100644
--- a/content/docs/command-reference/exp/run.md
+++ b/content/docs/command-reference/exp/run.md
@@ -154,10 +154,10 @@ CPU cores).
 > `dvc repro`, with the exception that `--no-commit` has no effect here.
 
 - `-S [<filename>:]<param_name>=<param_value>`,
-  `--set-param [<filename>:]<param_name>=<param_value>` - set the specified
-  `dvc params` for this experiment. `filename` can be any valid params file
-  (`params.yaml` by default). This will override the param values coming from
-  the params file.
+  `--set-param [<filename>:]<param_name>=<param_value>` - set the value of
+  existing `dvc params` for this experiment. `filename` can be any valid params
+  file (`params.yaml` by default). This will override the param values coming
+  from the params file.
 
 - `-n <name>`, `--name <name>` - specify a name for this experiment. A default
   name will generated by default, such as `exp-f80g4` (based on the experiment's
@@ -258,8 +258,8 @@ experiment we just ran (`exp-44136`).
 
 You could modify a params file just like any other <abbr>dependency</abbr> and
 run an experiment on that basis. Since this is a common need, `dvc exp run`
-comes with the `--set-param` (`-S`) option built-in. This saves you the need to
-manually edit the params file:
+comes with the `--set-param` (`-S`) option built-in to update existing
+parameters. This saves you the need to manually edit the params file.
 
 ```dvc
 $ dvc exp run -S prepare.split=0.25 -S featurize.max_features=2000
diff --git a/content/docs/user-guide/experiment-management/running-experiments.md b/content/docs/user-guide/experiment-management/running-experiments.md
index 6f3a3dc51c..bfa7dff3e8 100644
--- a/content/docs/user-guide/experiment-management/running-experiments.md
+++ b/content/docs/user-guide/experiment-management/running-experiments.md
@@ -146,12 +146,17 @@ $ dvc exp run -S myparams.toml:learning_rate = 0.0001
 
 ### Updating experiment parameters on-the-fly
 
-DVC allows to update the parameters from command line when running experiments.
-The `--set-param` (`-S`) option takes a parameter name and its value, and
+DVC allows to update parameters from command line when running experiments. The
+`--set-param` (`-S`) option takes an existing parameter name and its value, and
 updates the params file before the run.
 
 ```dvc
+$ cat params.yaml
+model:
+  learning_rate: 0.001
+
 $ dvc exp run --set-param model.learning_rate=0.0002
+...
 ```
 
 > Note that parameters are attached to experiments so you can view them together
@@ -164,10 +169,6 @@ times:
 $ dvc exp run -S learning_rate=0.001 -S units=128
 ```
 
-> ⚠️ Note that DVC doesn't check whether parameters given to `--set-param` are
-> already in the parameters file. If there is a typo, a new or different param
-> will be added/changed.
-
 ## The experiments queue
 
 The `--queue` option of `dvc exp run` tells DVC to append an experiment for