diff --git a/snow/consensus/avalanche/consensus.go b/snow/consensus/avalanche/consensus.go
index d88a355..d2c4f3a 100644
--- a/snow/consensus/avalanche/consensus.go
+++ b/snow/consensus/avalanche/consensus.go
@@ -77,7 +77,8 @@ type Vertex interface {
 	// Returns the vertices this vertex depends on
 	Parents() []Vertex
 
-	// Returns the height of this vertex
+	// Returns the height of this vertex. A vertex's height is defined by one
+	// greater than the maximum height of the parents.
 	Height() uint64
 
 	// Returns a series of state transitions to be performed on acceptance