diff --git a/java/com/google/gerrit/index/project/ProjectPredicate.java b/java/com/google/gerrit/index/project/ProjectPredicate.java
index 4926eef..11875ef 100644
--- a/java/com/google/gerrit/index/project/ProjectPredicate.java
+++ b/java/com/google/gerrit/index/project/ProjectPredicate.java
@@ -17,6 +17,7 @@
 import com.google.gerrit.index.FieldDef;
 import com.google.gerrit.index.query.IndexPredicate;
 
+/** Predicate that is mapped to a field in the project index. */
 public class ProjectPredicate extends IndexPredicate<ProjectData> {
   public ProjectPredicate(FieldDef<ProjectData, ?> def, String value) {
     super(def, value);
diff --git a/java/com/google/gerrit/index/query/IndexPredicate.java b/java/com/google/gerrit/index/query/IndexPredicate.java
index 7811a32..aac6682 100644
--- a/java/com/google/gerrit/index/query/IndexPredicate.java
+++ b/java/com/google/gerrit/index/query/IndexPredicate.java
@@ -17,7 +17,7 @@
 import com.google.gerrit.index.FieldDef;
 import com.google.gerrit.index.FieldType;
 
-/** Index-aware predicate that includes a field type annotation. */
+/** Predicate that is mapped to a field in the index. */
 public abstract class IndexPredicate<I> extends OperatorPredicate<I> {
   private final FieldDef<I, ?> def;
 
diff --git a/java/com/google/gerrit/server/query/account/AccountPredicates.java b/java/com/google/gerrit/server/query/account/AccountPredicates.java
index 1eed7ea..fecfc31 100644
--- a/java/com/google/gerrit/server/query/account/AccountPredicates.java
+++ b/java/com/google/gerrit/server/query/account/AccountPredicates.java
@@ -130,6 +130,7 @@
     return new CanSeeChangePredicate(args.permissionBackend, changeNotes);
   }
 
+  /** Predicate that is mapped to a field in the account index. */
   static class AccountPredicate extends IndexPredicate<AccountState>
       implements Matchable<AccountState> {
     AccountPredicate(FieldDef<AccountState, ?> def, String value) {
diff --git a/java/com/google/gerrit/server/query/change/ChangeIndexPredicate.java b/java/com/google/gerrit/server/query/change/ChangeIndexPredicate.java
index 7428e3a..a176a58 100644
--- a/java/com/google/gerrit/server/query/change/ChangeIndexPredicate.java
+++ b/java/com/google/gerrit/server/query/change/ChangeIndexPredicate.java
@@ -19,6 +19,7 @@
 import com.google.gerrit.index.query.Matchable;
 import com.google.gerrit.index.query.Predicate;
 
+/** Predicate that is mapped to a field in the change index. */
 public abstract class ChangeIndexPredicate extends IndexPredicate<ChangeData>
     implements Matchable<ChangeData> {
   /**
diff --git a/java/com/google/gerrit/server/query/group/GroupPredicates.java b/java/com/google/gerrit/server/query/group/GroupPredicates.java
index 17a7000..b81ae99 100644
--- a/java/com/google/gerrit/server/query/group/GroupPredicates.java
+++ b/java/com/google/gerrit/server/query/group/GroupPredicates.java
@@ -63,6 +63,7 @@
     return new GroupPredicate(GroupField.SUBGROUP, subgroupUuid.get());
   }
 
+  /** Predicate that is mapped to a field in the group index. */
   static class GroupPredicate extends IndexPredicate<InternalGroup> {
     GroupPredicate(FieldDef<InternalGroup, ?> def, String value) {
       super(def, value);