Add required flag.

src/Infrastructure/BotSharp.Core/Routing/Handlers/RouteToAgentRoutingHandler.cs

@@ -14,9 +14,18 @@ public class RouteToAgentRoutingHandler : RoutingHandlerBase, IRoutingHandler
 
     public List<ParameterPropertyDef> Parameters => new List<ParameterPropertyDef>
     {
-        new ParameterPropertyDef("reason", "why route to agent"),
-        new ParameterPropertyDef("next_action_agent", "agent for next action based on user latest response"),
-        new ParameterPropertyDef("user_goal_agent", "agent who can achieve user original goal"),
+        new ParameterPropertyDef("reason", "why route to agent") 
+        { 
+            Required = true 
+        },
+        new ParameterPropertyDef("next_action_agent", "agent for next action based on user latest response")
+        {
+            Required = true
+        },
+        new ParameterPropertyDef("user_goal_agent", "agent who can achieve user original goal")
+        {
+            Required = true
+        },
         new ParameterPropertyDef("args", "useful parameters of next action agent, format: { }")
         {
             Type = "object"

src/Infrastructure/BotSharp.Core/Routing/RoutingService.InvokeFunction.cs

@@ -12,6 +12,7 @@ public partial class RoutingService
         var originalFunctionName = message.FunctionName;
         message.FunctionName = name;
         message.Role = AgentRole.Function;
+        message.FunctionArgs = message.FunctionArgs;
         var result = await function.Execute(message);
 
         // restore original function name

src/Infrastructure/BotSharp.Core/data/agents/01fcc3e5-9af7-49e6-ad7a-a760bd12dc4a/instruction.liquid

@@ -13,7 +13,7 @@ You're {{router.name}} ({{router.description}}). Follow these steps to handle us
 Parameters: 
     - function: {{ handler.name }}
     {% for p in handler.parameters -%}
-    - {{ p.name }}: {{ p.description }}{{ "\r\n    " }}
+    - {{ p.name }} {% if p.required -%}(required){%- endif %}: {{ p.description }}{{ "\r\n    " }}
     {%- endfor %}
 {%- endif %}
 {% endfor %}