diff --git a/pulsar-client-tools/src/main/java/org/apache/pulsar/admin/cli/CmdNamespaces.java b/pulsar-client-tools/src/main/java/org/apache/pulsar/admin/cli/CmdNamespaces.java
index 6bd9617c37674..5901d7c177ea7 100644
--- a/pulsar-client-tools/src/main/java/org/apache/pulsar/admin/cli/CmdNamespaces.java
+++ b/pulsar-client-tools/src/main/java/org/apache/pulsar/admin/cli/CmdNamespaces.java
@@ -2321,14 +2321,14 @@ public boolean isS3Driver(String driver) {
 
         public boolean positiveCheck(String paramName, long value) {
             if (value <= 0) {
-                throw new ParameterException(paramName + " is not be negative or 0!");
+                throw new ParameterException(paramName + " cannot be less than or equal to 0!");
             }
             return true;
         }
 
         public boolean maxValueCheck(String paramName, long value, long maxValue) {
             if (value > maxValue) {
-                throw new ParameterException(paramName + " is not bigger than " + maxValue + "!");
+                throw new ParameterException(paramName + " cannot be greater than " + maxValue + "!");
             }
             return true;
         }
diff --git a/pulsar-client-tools/src/main/java/org/apache/pulsar/admin/cli/CmdTopics.java b/pulsar-client-tools/src/main/java/org/apache/pulsar/admin/cli/CmdTopics.java
index b07ad0056617e..959249bf0fb42 100644
--- a/pulsar-client-tools/src/main/java/org/apache/pulsar/admin/cli/CmdTopics.java
+++ b/pulsar-client-tools/src/main/java/org/apache/pulsar/admin/cli/CmdTopics.java
@@ -2198,14 +2198,14 @@ public boolean isS3Driver(String driver) {
 
         public boolean positiveCheck(String paramName, long value) {
             if (value <= 0) {
-                throw new ParameterException(paramName + " is not be negative or 0!");
+                throw new ParameterException(paramName + " cannot be less than or equal to 0!");
             }
             return true;
         }
 
         public boolean maxValueCheck(String paramName, long value, long maxValue) {
             if (value > maxValue) {
-                throw new ParameterException(paramName + " is not bigger than " + maxValue + "!");
+                throw new ParameterException(paramName + " cannot be greater than " + maxValue + "!");
             }
             return true;
         }