diff --git a/security/s2a/internal/authinfo/authinfo.go b/security/s2a/internal/authinfo/authinfo.go
index 987140146497..1858e19df0e9 100644
--- a/security/s2a/internal/authinfo/authinfo.go
+++ b/security/s2a/internal/authinfo/authinfo.go
@@ -16,6 +16,10 @@
  *
  */
 
+/*
+Package authinfo provides authentication and authorization information from the
+S2A session result to the gRPC stack.
+*/
 package authinfo
 
 import (
diff --git a/security/s2a/internal/fakehandshaker/main.go b/security/s2a/internal/fakehandshaker/main.go
index 2efd3be4d8d3..7f8ceff4e3f1 100644
--- a/security/s2a/internal/fakehandshaker/main.go
+++ b/security/s2a/internal/fakehandshaker/main.go
@@ -16,6 +16,7 @@
  *
  */
 
+// The fakehandshaker binary provides a fake handshaker service for S2A.
 package main
 
 import (
diff --git a/security/s2a/internal/handshaker/handshaker.go b/security/s2a/internal/handshaker/handshaker.go
index 952bea278573..bd4784de57cb 100644
--- a/security/s2a/internal/handshaker/handshaker.go
+++ b/security/s2a/internal/handshaker/handshaker.go
@@ -16,6 +16,7 @@
  *
  */
 
+// Package handshaker implements the S2A handshaker service.
 package handshaker
 
 import (
diff --git a/security/s2a/internal/record/internal/aeadcrypter/aeadcrypter.go b/security/s2a/internal/record/internal/aeadcrypter/aeadcrypter.go
index 1f583eb3f9d3..9a0f48bbc70c 100644
--- a/security/s2a/internal/record/internal/aeadcrypter/aeadcrypter.go
+++ b/security/s2a/internal/record/internal/aeadcrypter/aeadcrypter.go
@@ -16,6 +16,10 @@
  *
  */
 
+/*
+Package aeadcrypter provides the interface for AEAD Crypter implementations
+used by S2A.
+*/
 package aeadcrypter
 
 // S2AAEADCrypter is the interface for an AEAD cipher used by the S2A record
diff --git a/security/s2a/internal/record/internal/halfconn/halfconn.go b/security/s2a/internal/record/internal/halfconn/halfconn.go
index 37887937e84c..714bd3039440 100644
--- a/security/s2a/internal/record/internal/halfconn/halfconn.go
+++ b/security/s2a/internal/record/internal/halfconn/halfconn.go
@@ -16,6 +16,10 @@
  *
  */
 
+/*
+Package halfconn implements a half connection for managing one side of a TLS 1.3
+connection.
+*/
 package halfconn
 
 import (
diff --git a/security/s2a/internal/record/record.go b/security/s2a/internal/record/record.go
index 5eba95f5b731..93c0178d8b6d 100644
--- a/security/s2a/internal/record/record.go
+++ b/security/s2a/internal/record/record.go
@@ -16,6 +16,7 @@
  *
  */
 
+// Package record implements the TLS 1.3 record protocol.
 package record
 
 import (
diff --git a/security/s2a/s2a.go b/security/s2a/s2a.go
index b4fbfd53628d..32b740671664 100644
--- a/security/s2a/s2a.go
+++ b/security/s2a/s2a.go
@@ -16,6 +16,9 @@
  *
  */
 
+/*
+Package s2a provides the S2A transport credentials used by gRPC.
+*/
 package s2a
 
 import (