diff --git a/v2/netmap/grpc/service.pb.go b/v2/netmap/grpc/service.pb.go
index c7864c8..a56abe4 100644
--- a/v2/netmap/grpc/service.pb.go
+++ b/v2/netmap/grpc/service.pb.go
@@ -171,6 +171,7 @@ func (x *LocalNodeInfoResponse) GetVerifyHeader() *grpc.ResponseVerificationHead
 	return nil
 }
 
+// Get NetworkInfo structure with the network view from particular node.
 type NetworkInfoRequest struct {
 	state         protoimpl.MessageState
 	sizeCache     protoimpl.SizeCache
@@ -240,6 +241,8 @@ func (x *NetworkInfoRequest) GetVerifyHeader() *grpc.RequestVerificationHeader {
 	return nil
 }
 
+// Response with NetworkInfo structure including current epoch and
+// sidechain magic number.
 type NetworkInfoResponse struct {
 	state         protoimpl.MessageState
 	sizeCache     protoimpl.SizeCache
diff --git a/v2/object/grpc/service.pb.go b/v2/object/grpc/service.pb.go
index 8f0ea63..81a9c41 100644
--- a/v2/object/grpc/service.pb.go
+++ b/v2/object/grpc/service.pb.go
@@ -1910,6 +1910,11 @@ func (x *SearchRequest_Body) GetFilters() []*SearchRequest_Body_Filter {
 // Filter structure checks if object header field or attribute content
 // matches a value.
 //
+// If no filters set, search request will return all objects of the
+// container, including Regular object, Tombstones and Storage Group
+// objects. Most human users expect to get only object they can directly
+// work with. In that case the `$Object:ROOT` filter should be used.
+//
 // By default `key` field refers to the corresponding object's `Attribute`.
 // Some Object's header fields can also be accessed by adding `$Object:`
 // prefix to the name. Here is the list of fields available via this prefix:
diff --git a/v2/tombstone/grpc/types.pb.go b/v2/tombstone/grpc/types.pb.go
index d14e2b9..c7a7dc0 100644
--- a/v2/tombstone/grpc/types.pb.go
+++ b/v2/tombstone/grpc/types.pb.go
@@ -34,7 +34,9 @@ type Tombstone struct {
 	unknownFields protoimpl.UnknownFields
 
 	// Last NeoFS epoch number of the tombstone lifetime. It's set by tombstone
-	// creator depending on current NeoFS network settings.
+	// creator depending on current NeoFS network settings. Tombstone object
+	// must have the same expiration epoch value in `__NEOFS__EXPIRATION_EPOCH`
+	// attribute. Otherwise tombstone will be rejected by storage node.
 	ExpirationEpoch uint64 `protobuf:"varint,1,opt,name=expiration_epoch,json=expirationEpoch,proto3" json:"expiration_epoch,omitempty"`
 	// 16 byte UUID used to identify the split object hierarchy parts. Must be
 	// unique inside container. All objects participating in the split must