diff --git a/docs/openapi.json b/docs/openapi.json
index 0a40e8bc..46556865 100644
--- a/docs/openapi.json
+++ b/docs/openapi.json
@@ -1531,10 +1531,10 @@
         "type": "object",
         "required": [
           "name",
-          "arguments"
+          "parameters"
         ],
         "properties": {
-          "arguments": {},
+          "parameters": {},
           "description": {
             "type": "string",
             "nullable": true
@@ -2282,7 +2282,14 @@
         ],
         "properties": {
           "function": {
-            "$ref": "#/components/schemas/FunctionDefinition"
+            "oneOf": [
+              {
+                "$ref": "#/components/schemas/FunctionDefinition"
+              },
+              {
+                "$ref": "#/components/schemas/FunctionCall"
+              }
+            ]
           },
           "type": {
             "type": "string",
diff --git a/router/src/infer/chat_template.rs b/router/src/infer/chat_template.rs
index 60f13d08..56a8616c 100644
--- a/router/src/infer/chat_template.rs
+++ b/router/src/infer/chat_template.rs
@@ -1193,6 +1193,43 @@ TOOL CALL ID: 0
         assert_eq!(result.unwrap(), expected);
     }
 
+    #[test]
+    fn test_chat_template_with_default_tool_template_arguments_deprecated() {
+        let ct = ChatTemplate::new(
+            "{{ bos_token }}{% for message in messages %}{% if (message['role'] == 'user') != (loop.index0 % 2 == 0) %}{{ raise_exception('Conversation roles must alternate user/assistant/user/assistant/...') }}{% endif %}{% if message['role'] == 'user' %}{{ '[INST] ' + message['content'] + ' [/INST]' }}{% elif message['role'] == 'assistant' %}{{ message['content'] + eos_token + ' ' }}{% else %}{{ raise_exception('Only user and assistant roles are supported!') }}{% endif %}{% endfor %}".to_string(),
+            Some(TokenizerConfigToken::String("<s>".to_string())),
+            Some(TokenizerConfigToken::String("</s>".to_string())),
+        );
+
+        // convert TextMessage to Message
+        let msgs: Vec<Message> = vec![
+            Message {
+                name: None,
+                role: "user".to_string(),
+                content: MessageContent::SingleText(
+                    "I'd like to show off how chat templating works!".to_string(),
+                ),
+            },
+            Message {
+                name: None,
+                role: "assistant".to_string(),
+                content: MessageContent::SingleText("Great! How can I help you today?".to_string()),
+            },
+            Message {
+                name: None,
+                role: "user".to_string(),
+                content: MessageContent::SingleText("Just testing".to_string()),
+            },
+        ];
+        let tools_string = r#"[{"type": "function","function": {"name": "get_current_weather","description": "Get the current weather","arguments": {"type": "object","properties": {"location": {"type": "string","description": "The city and state, e.g. San Francisco, CA"},"format": {"type": "string","enum": ["celsius", "fahrenheit"],"description": "The temperature unit to use. Infer this from the users location."}},"required": ["location", "format"]}}}]"#.to_string();
+        let tools: Vec<Tool> = serde_json::from_str(&tools_string).unwrap();
+        let tool_prompt = "This default prompt will be used".to_string();
+        let tools_and_prompt = Some((tools, tool_prompt));
+        let result = ct.apply(msgs, tools_and_prompt);
+        let expected = "<s>[INST] I'd like to show off how chat templating works! [/INST]Great! How can I help you today?</s> [INST] Just testing\n---\n[{\"type\":\"function\",\"function\":{\"description\":\"Get the current weather\",\"name\":\"get_current_weather\",\"parameters\":{\"type\":\"object\",\"properties\":{\"location\":{\"type\":\"string\",\"description\":\"The city and state, e.g. San Francisco, CA\"},\"format\":{\"type\":\"string\",\"enum\":[\"celsius\",\"fahrenheit\"],\"description\":\"The temperature unit to use. Infer this from the users location.\"}},\"required\":[\"location\",\"format\"]}}}]\nThis default prompt will be used [/INST]".to_string();
+        assert_eq!(result.unwrap(), expected);
+    }
+
     #[test]
     fn test_chat_template_with_custom_tool_template() {
         // chat template from meta-llama/Meta-Llama-3.1-8B-Instruct
diff --git a/router/src/lib.rs b/router/src/lib.rs
index 0d828843..1932b06b 100644
--- a/router/src/lib.rs
+++ b/router/src/lib.rs
@@ -1135,6 +1135,7 @@ pub struct FunctionDefinition {
     #[serde(default)]
     pub description: Option<String>,
     pub name: String,
+    #[serde(alias = "arguments")]
     pub parameters: serde_json::Value,
 }