diff --git a/python-backcall.spec b/python-backcall.spec
index 2961b0c..dc7d910 100644
--- a/python-backcall.spec
+++ b/python-backcall.spec
@@ -10,7 +10,9 @@ BuildArch:	noarch
 
 
 %description
-
+If your code lets other people supply callback functions, it's important to
+specify the function signature you expect, and check that functions support that.
+Adding extra parameters later would break other peoples code unless you're careful.
 
 %package -n python3-backcall
 Summary:	Specifications for callback functions passed in to an API
@@ -18,13 +20,17 @@ Provides:	python-backcall
 BuildRequires:	python3-devel
 BuildRequires:	python3-setuptools
 %description -n python3-backcall
-
+If your code lets other people supply callback functions, it's important to
+specify the function signature you expect, and check that functions support that.
+Adding extra parameters later would break other peoples code unless you're careful.
 
 %package help
 Summary:	Development documents and examples for backcall
 Provides:	python3-backcall-doc
 %description help
-
+If your code lets other people supply callback functions, it's important to
+specify the function signature you expect, and check that functions support that.
+Adding extra parameters later would break other peoples code unless you're careful.
 
 %prep
 %autosetup -n backcall-0.2.0