diff --git a/models/Agent.json b/models/Agent.json
index 584c9ce..610526e 100644
--- a/models/Agent.json
+++ b/models/Agent.json
@@ -9,7 +9,7 @@
     },
     "symbol": {
       "type": "string",
-      "minLength": 1,
+      "minLength": 3,
       "maxLength": 14,
       "description": "Symbol of the agent."
     },