diff --git a/cmd/uncloud/service/exec.go b/cmd/uncloud/service/exec.go
index 59dcbdf7..95b8c26e 100644
--- a/cmd/uncloud/service/exec.go
+++ b/cmd/uncloud/service/exec.go
@@ -74,7 +74,8 @@ If the service has multiple replicas and no container ID is specified, the comma
 
 	// Common flags
 	execCmd.Flags().StringVar(&opts.containerId, "container", "",
-		"ID of the container to exec into (default is the random container of the service)")
+		"ID of the container to exec into. Accepts full ID or a unique prefix "+
+			"(default is the random container of the service)")
 
 	// This tells Cobra that all flags must come before positional arguments, so that
 	// commands with their own flags can be handled correctly.
diff --git a/website/docs/9-cli-reference/uc_exec.md b/website/docs/9-cli-reference/uc_exec.md
index afdeb611..41bae341 100644
--- a/website/docs/9-cli-reference/uc_exec.md
+++ b/website/docs/9-cli-reference/uc_exec.md
@@ -35,7 +35,7 @@ uc exec [OPTIONS] SERVICE [COMMAND ARGS...] [flags]
 ## Options
 
 ```
-      --container string   ID of the container to exec into (default is the random container of the service)
+      --container string   ID of the container to exec into. Accepts full ID or a unique prefix (default is the random container of the service)
   -c, --context string     Name of the cluster context. (default is the current context)
   -d, --detach             Detached mode: run command in the background
   -h, --help               help for exec
diff --git a/website/docs/9-cli-reference/uc_service_exec.md b/website/docs/9-cli-reference/uc_service_exec.md
index 9c8a5616..572970e1 100644
--- a/website/docs/9-cli-reference/uc_service_exec.md
+++ b/website/docs/9-cli-reference/uc_service_exec.md
@@ -35,7 +35,7 @@ uc service exec [OPTIONS] SERVICE [COMMAND ARGS...] [flags]
 ## Options
 
 ```
-      --container string   ID of the container to exec into (default is the random container of the service)
+      --container string   ID of the container to exec into. Accepts full ID or a unique prefix (default is the random container of the service)
   -c, --context string     Name of the cluster context. (default is the current context)
   -d, --detach             Detached mode: run command in the background
   -h, --help               help for exec