diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTracker.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTracker.java
index b845bd0..5df083d 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTracker.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTracker.java
@@ -1,8 +1,30 @@
 package edu.uci.ics.hyracks.storage.am.lsm.common.api;
 
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexAccessor;
 
+/**
+ * This interface exposes methods for tracking when operations (e.g. insert, search) 
+ * enter and exit an {@link ILSMIndex}.
+ * 
+ * Note that 'operation' below refers to {@link IIndexAccessor} methods.
+ *  
+ * @author zheilbron
+ */
 public interface ILSMOperationTracker {
+
+    /**
+     * This method is guaranteed to be called whenever an operation first begins on the index, 
+     * before any traversals of the index structures (more specifically, before any 
+     * pages are pinned/latched).
+     * 
+     * @param index the index for which the operation entered
+     */
     public void threadEnter(ILSMIndex index);
 
+    /**
+     * This method is guaranteed to be called just before an operation is finished on the index.
+     * 
+     * @param index the index for which the operation exited
+     */
     public void threadExit(ILSMIndex index);
 }