diff --git a/src/ludus/analyzer.clj b/src/ludus/analyzer.clj
index 4e1105f..d321576 100644
--- a/src/ludus/analyzer.clj
+++ b/src/ludus/analyzer.clj
@@ -17,4 +17,5 @@
 	* Enforce single-member tuple after called keywords
 	* Placeholders may only appear in tuples in synthetic expressions
 	* Each of these may have zero or one placeholders
+	* Arity of called keywords must be 1
 ")
\ No newline at end of file