--- a/hicSumMatrices.xml	Mon Nov 27 11:17:35 2017 -0500
+++ b/hicSumMatrices.xml	Sat Dec 16 16:35:53 2017 -0500
@@ -31,11 +31,30 @@
         </test>
     </tests>
     <help><![CDATA[
+Summation of matrices
+=====================
 
-**What it does**
+``hicSumMatrix`` is combining two (or more) contact matrices of the same size to one. 
+This is useful if replicates of an Hi-C experiment should be merged into one contact matrix to 
+increase the power of the data. It is the nature of Hi-C that real contact cannot be distinguished
+ from noise, especially with a low contact count. The more contacts are given, the more likely it is 
+ that a high number of contacts are real contact or contain at least a high amount. Therefore it is 
+ a common way to merge replicates of Hi-C experiments to increase the validity of the experiment.
 
-Combines Hi-C matrices of the same size.
+Input
+-----
+
+Parameters
+__________
+- two or matrices of the same shape.
 
+Output
+------
+The summed matrix.
+
+| For more information about HiCExplorer please consider our documentation on readthedocs.io_
+
+.. _readthedocs.io: http://hicexplorer.readthedocs.io/en/latest/index.html
 ]]></help>
     <expand macro="citations" />
 </tool>