diff --git a/crates/agent-describe/src/lib.rs b/crates/agent-describe/src/lib.rs
index db0cfb0..5a38de7 100644
--- a/crates/agent-describe/src/lib.rs
+++ b/crates/agent-describe/src/lib.rs
@@ -1,3 +1,5 @@
+//! Self-describing CLI protocol for AI agents (`agent-cli/1`).
+
 pub use agent_describe_derive::AgentDescribe;
 
 pub mod response;