diff --git a/README.md b/README.md
index 3a9f3c3..02fc208 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,15 @@ Also, HoardD was made to be used with chef (or any other configuration managemen
 
 The master branch will be updated only to working versions (i.e: I will *try* not to break it), so you can probably just do a clone/fetch/pull from it on new versions.
 
+### Scripts and specific configuration
+
+The MySQL script is an example of how to configure specific scripts. It contains a `mysql.json` file that is read by the script when it starts. Just make sure to:
+
+* Keep the configs with the same name as the plugin (like, mysql.coffee and mysql.json)
+* Put/link the configuration on the script path (together with the scripts)
+
+For real, you can do whatever you want on your scripts, but it's better to make it easier for other people to configure/understand, so let's stick to a default.
+
 Retentions, sample interval and counter metrics
 ------------------------------------------------
 
@@ -38,6 +47,12 @@ Counter metrics are ever increasing counters, like the ones used on `/proc/net/i
 
 **TL;DR**: use `derivative` to make the graph show differences between two samples and `scale` to make it show per second. The scale is always 1/*data retention value* of the graph.
 
+For example, for network speed:
+
+```
+scale(derivative(hoard.host.interfaces.eth0.txBytes),0.1)
+```
+
 Writing new scripts
 --------------------
 
diff --git a/scripts-available/mysql.coffee b/scripts-available/mysql.coffee
index 90a5c0b..6e78df7 100644
--- a/scripts-available/mysql.coffee
+++ b/scripts-available/mysql.coffee
@@ -2,6 +2,8 @@ Mysql = require 'mysql'
 Fs    = require 'fs'
 Path  = require 'path'
 
+# To configure this plugin use the mysql.json file and put it on the scripts/ directory
+
 # Metrics to get from the statuses
 generalMetrics = 
   'rxBytes':                  'Bytes_received',
@@ -98,14 +100,14 @@ module.exports = (server) ->
     conn = Mysql.createClient conf
     conn.query 'SHOW GLOBAL STATUS', (err, res, fields) ->
       if err
-        server.cli "Error on STATUS query: #{err}"
+        server.cli.error "Error on STATUS query: #{err}"
 
       for row in res
         data[row.Variable_name] = row.Value
 
       conn.query 'SHOW SLAVE STATUS', (err, res, fields) ->
         if err
-          server.cli "Error on SLAVE STATUS query: #{err}"
+          server.cli.error "Error on SLAVE STATUS query: #{err}"
 
         data[key] = value for key, value of res[0]