diff --git a/Code/Mantid/Framework/Algorithms/src/SANSCollimationLengthEstimator.cpp b/Code/Mantid/Framework/Algorithms/src/SANSCollimationLengthEstimator.cpp
index bf318676a134e28c69a407d1bca1be357bdd6dc1..8f85b822d70bf81ecf207690c0f46c5320640e48 100644
--- a/Code/Mantid/Framework/Algorithms/src/SANSCollimationLengthEstimator.cpp
+++ b/Code/Mantid/Framework/Algorithms/src/SANSCollimationLengthEstimator.cpp
@@ -58,7 +58,9 @@ double SANSCollimationLengthEstimator::provideCollimationLength(Mantid::API::Mat
 
 
 /**
- * This extraction strategy gets applied when guides are
+ * This extraction strategy gets applied when guides are used to calculate the collimation length. The instrument
+ * parameter file contains the information about the number of guides to use. The guide data itself is fetched
+ * from the sample logs.
  * @param inOutWS: a matrix workspace
  * @param L1: the distance between sample and source
  * @param collimationLengthCorrection: The correction to get the collimation length