diff --git a/sd/consul/doc.go b/sd/consul/doc.go
new file mode 100644
index 0000000..ae51c44
--- /dev/null
+++ b/sd/consul/doc.go
@@ -0,0 +1,2 @@
+// Package consul provides subscriber and registrar implementations for Consul.
+package consul
diff --git a/sd/dnssrv/doc.go b/sd/dnssrv/doc.go
new file mode 100644
index 0000000..7bc1ad4
--- /dev/null
+++ b/sd/dnssrv/doc.go
@@ -0,0 +1,2 @@
+// Package dnssrv provides a subscriber implementation for DNS SRV records.
+package dnssrv
diff --git a/sd/etcd/doc.go b/sd/etcd/doc.go
new file mode 100644
index 0000000..f8bd5bf
--- /dev/null
+++ b/sd/etcd/doc.go
@@ -0,0 +1,2 @@
+// Package etcd provides a subscriber implementation for etcd.
+package etcd
diff --git a/sd/lb/doc.go b/sd/lb/doc.go
index 82a9516..92aea81 100644
--- a/sd/lb/doc.go
+++ b/sd/lb/doc.go
@@ -1,5 +1,4 @@
-// Package lb deals with client-side load balancing across multiple identical
-// instances of services and endpoints. When combined with a service discovery
-// system of record, it enables a more decentralized architecture, removing the
-// need for separate load balancers like HAProxy.
+// Package lb implements the client-side load balancer pattern. When combined
+// with a service discovery system of record, it enables a more decentralized
+// architecture, removing the need for separate load balancers like HAProxy.
 package lb
diff --git a/sd/zk/doc.go b/sd/zk/doc.go
new file mode 100644
index 0000000..02c2208
--- /dev/null
+++ b/sd/zk/doc.go
@@ -0,0 +1,2 @@
+// Package zk provides subscriber and registrar implementations for ZooKeeper.
+package zk