Further clarify #20

README.md

@@ -41,8 +41,9 @@ Requiring the gem in your gemfile should be sufficient to enable unique jobs.
 
 ### Finer Control over Uniqueness
 
-Sometimes it is desired to have a finer control over which arguments are used in determining uniqueness of the job, and others may be _transient_. For this use-case, you need to
-set `SidekiqUniqueJobs::Config.unique_args_enabled` to true in an initializer, and then defined either `unique_args` method, or a ruby proc.
+Sometimes it is desired to have a finer control over which arguments are used in determining uniqueness of the job, and others may be _transient_. For this use-case, you need to set `SidekiqUniqueJobs::Config.unique_args_enabled` to true in an initializer, and then defined either `unique_args` method, or a ruby proc.
+
+The unique_args method need to return an array of values to use for uniqueness check.
 
 ```ruby
 SidekiqUniqueJobs::Config.unique_args_enabled = true
@@ -74,10 +75,7 @@ class UniqueJobWithFilterProc
 end
 ```
 
-Note that objects passed into workers are converted to JSON *after* running through client middleware. In server
-middleware, the JSON is passed directly to the worker `#perform` method. So, you may run into issues where the
-arguments are different when enqueuing than they are when performing. Your `unique_args` method may need to
-account for this.
+Note that objects passed into workers are converted to JSON *after* running through client middleware. In server middleware, the JSON is passed directly to the worker `#perform` method. So, you may run into issues where the arguments are different when enqueuing than they are when performing. Your `unique_args` method may need to account for this.
 
 ### Unlock Ordering