diff --git a/router/src/infer/chat_template.rs b/router/src/infer/chat_template.rs
index e660cc74..60f13d08 100644
--- a/router/src/infer/chat_template.rs
+++ b/router/src/infer/chat_template.rs
@@ -1189,7 +1189,7 @@ TOOL CALL ID: 0
         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\",\"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\"]}}}]\nThis default prompt will be used [/INST]".to_string();
+        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);
     }
 
@@ -1227,7 +1227,7 @@ TOOL CALL ID: 0
         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><|start_header_id|>system<|end_header_id|>\n\nEnvironment: ipython\nCutting Knowledge Date: December 2023\nToday Date: 26 Jul 2024\n\nYoure a helpful assistant! Answer the users question best you can.<|eot_id|><|start_header_id|>user<|end_header_id|>\n\nGiven the following functions, please respond with a JSON for a function call with its proper arguments that best answers the given prompt.\n\nRespond in the format {\"name\": function name, \"parameters\": dictionary of argument name and its value}.Do not use variables.\n\n{\n    \"function\": {\n        \"arguments\": {\n            \"properties\": {\n                \"format\": {\n                    \"description\": \"The temperature unit to use. Infer this from the users location.\",\n                    \"enum\": [\n                        \"celsius\",\n                        \"fahrenheit\"\n                    ],\n                    \"type\": \"string\"\n                },\n                \"location\": {\n                    \"description\": \"The city and state, e.g. San Francisco, CA\",\n                    \"type\": \"string\"\n                }\n            },\n            \"required\": [\n                \"location\",\n                \"format\"\n            ],\n            \"type\": \"object\"\n        },\n        \"description\": \"Get the current weather\",\n        \"name\": \"get_current_weather\"\n    },\n    \"type\": \"function\"\n}\n\nWhat is the weather like in Brooklyn, New York?\n---\nThis default prompt will be used<|eot_id|><|start_header_id|>assistant<|end_header_id|>\n\n".to_string();
+        let expected = "<s><|start_header_id|>system<|end_header_id|>\n\nEnvironment: ipython\nCutting Knowledge Date: December 2023\nToday Date: 26 Jul 2024\n\nYoure a helpful assistant! Answer the users question best you can.<|eot_id|><|start_header_id|>user<|end_header_id|>\n\nGiven the following functions, please respond with a JSON for a function call with its proper arguments that best answers the given prompt.\n\nRespond in the format {\"name\": function name, \"parameters\": dictionary of argument name and its value}.Do not use variables.\n\n{\n    \"function\": {\n        \"description\": \"Get the current weather\",\n        \"name\": \"get_current_weather\",\n        \"parameters\": {\n            \"properties\": {\n                \"format\": {\n                    \"description\": \"The temperature unit to use. Infer this from the users location.\",\n                    \"enum\": [\n                        \"celsius\",\n                        \"fahrenheit\"\n                    ],\n                    \"type\": \"string\"\n                },\n                \"location\": {\n                    \"description\": \"The city and state, e.g. San Francisco, CA\",\n                    \"type\": \"string\"\n                }\n            },\n            \"required\": [\n                \"location\",\n                \"format\"\n            ],\n            \"type\": \"object\"\n        }\n    },\n    \"type\": \"function\"\n}\n\nWhat is the weather like in Brooklyn, New York?\n---\nThis default prompt will be used<|eot_id|><|start_header_id|>assistant<|end_header_id|>\n\n".to_string();
         assert_eq!(result.unwrap(), expected);
     }
 }
diff --git a/router/src/infer/tool_grammar.rs b/router/src/infer/tool_grammar.rs
index 7770cd9d..6b6099f3 100644
--- a/router/src/infer/tool_grammar.rs
+++ b/router/src/infer/tool_grammar.rs
@@ -38,7 +38,7 @@ impl ToolGrammar {
                             description: Some(
                                 "Open ended response with no specific tool selected".to_string(),
                             ),
-                            arguments: json!({
+                            parameters: json!({
                                 "type": "object",
                                 "properties": {
                                     "content": {
@@ -83,7 +83,7 @@ impl ToolGrammar {
                     }),
                 );
 
-                if let Value::Object(args) = func.arguments {
+                if let Value::Object(args) = func.parameters {
                     if let Some(Value::Object(props)) = args.get("properties") {
                         properties.extend(props.clone());
                     }
diff --git a/router/src/lib.rs b/router/src/lib.rs
index 089e30df..0d828843 100644
--- a/router/src/lib.rs
+++ b/router/src/lib.rs
@@ -730,7 +730,7 @@ pub(crate) struct ChatCompletionChoice {
 pub struct ToolCallDelta {
     #[schema(example = "assistant")]
     role: String,
-    tool_calls: DeltaToolCall,
+    tool_calls: Vec<DeltaToolCall>,
 }
 
 #[derive(Clone, Debug, Serialize, ToSchema)]
@@ -745,11 +745,11 @@ pub(crate) struct DeltaToolCall {
     pub index: u32,
     pub id: String,
     pub r#type: String,
-    pub function: Function,
+    pub function: FunctionCallChunk,
 }
 
 #[derive(Clone, Deserialize, Serialize, ToSchema, Debug, PartialEq)]
-pub(crate) struct Function {
+pub(crate) struct FunctionCallChunk {
     pub name: Option<String>,
     pub arguments: String,
 }
@@ -760,7 +760,7 @@ impl ChatCompletionChunk {
         model: String,
         system_fingerprint: String,
         delta: Option<String>,
-        tool_calls: Option<Vec<String>>,
+        tool_calls: Option<FunctionCallChunk>,
         created: u64,
         logprobs: Option<ChatCompletionLogprobs>,
         finish_reason: Option<String>,
@@ -774,15 +774,12 @@ impl ChatCompletionChunk {
             }),
             (None, Some(tool_calls)) => ChatCompletionDelta::Tool(ToolCallDelta {
                 role: "assistant".to_string(),
-                tool_calls: DeltaToolCall {
+                tool_calls: vec![DeltaToolCall {
                     index: 0,
                     id: String::new(),
                     r#type: "function".to_string(),
-                    function: Function {
-                        name: None,
-                        arguments: tool_calls[0].to_string(),
-                    },
-                },
+                    function: tool_calls,
+                }],
             }),
             (None, None) => ChatCompletionDelta::Chat(TextMessage {
                 role: "assistant".to_string(),
@@ -1138,16 +1135,12 @@ pub struct FunctionDefinition {
     #[serde(default)]
     pub description: Option<String>,
     pub name: String,
-    #[serde(alias = "parameters")]
-    pub arguments: serde_json::Value,
+    pub parameters: serde_json::Value,
 }
 
 #[derive(Clone, Debug, Deserialize, Serialize, ToSchema, Default, PartialEq)]
 pub(crate) struct FunctionCall {
-    #[serde(default)]
-    pub description: Option<String>,
     pub name: String,
-    #[serde(alias = "parameters")]
     pub arguments: String,
 }
 
@@ -1728,7 +1721,6 @@ mod tests {
                 id: "0".to_string(),
                 r#type: "function".to_string(),
                 function: FunctionCall {
-                    description: None,
                     name: "myfn".to_string(),
                     arguments: json!({
                         "format": "csv"
@@ -1740,7 +1732,7 @@ mod tests {
         let serialized = serde_json::to_string(&message).unwrap();
         assert_eq!(
             serialized,
-            r#"{"role":"assistant","tool_calls":[{"id":"0","type":"function","function":{"description":null,"name":"myfn","arguments":"{\"format\":\"csv\"}"}}]}"#
+            r#"{"role":"assistant","tool_calls":[{"id":"0","type":"function","function":{"name":"myfn","arguments":"{\"format\":\"csv\"}"}}]}"#
         );
     }
 
diff --git a/router/src/server.rs b/router/src/server.rs
index 71e8c663..e267a951 100644
--- a/router/src/server.rs
+++ b/router/src/server.rs
@@ -13,8 +13,8 @@ use crate::sagemaker::{
 use crate::validation::ValidationError;
 use crate::vertex::vertex_compatibility;
 use crate::{
-    usage_stats, BestOfSequence, Details, ErrorResponse, FinishReason, FunctionName,
-    GenerateParameters, GenerateRequest, GenerateResponse, GrammarType, HubModelInfo,
+    usage_stats, BestOfSequence, Details, ErrorResponse, FinishReason, FunctionCallChunk,
+    FunctionName, GenerateParameters, GenerateRequest, GenerateResponse, GrammarType, HubModelInfo,
     HubProcessorConfig, HubTokenizerConfig, Info, Message, MessageChunk, MessageContent,
     OutputMessage, PrefillToken, SimpleToken, StreamDetails, StreamOptions, StreamResponse,
     TextMessage, Token, TokenizeResponse, Tokenizer, ToolCallDelta, ToolCallMessage, Url, Usage,
@@ -24,7 +24,7 @@ use crate::{
     ChatCompletion, ChatCompletionChoice, ChatCompletionChunk, ChatCompletionComplete,
     ChatCompletionDelta, ChatCompletionLogprob, ChatCompletionLogprobs, ChatCompletionTopLogprob,
     ChatRequest, Chunk, CompatGenerateRequest, Completion, CompletionComplete, CompletionFinal,
-    CompletionRequest, CompletionType, DeltaToolCall, Function, Prompt, Tool,
+    CompletionRequest, CompletionType, DeltaToolCall, Prompt, Tool,
 };
 use crate::{ChatTokenizeResponse, FunctionCall};
 use crate::{FunctionDefinition, HubPreprocessorConfig, ToolCall, ToolChoice};
@@ -1117,6 +1117,7 @@ pub(crate) async fn completions(
 enum StreamState {
     Buffering,
     BufferTrailing,
+    Arguments,
     Content { skip_close_quote: bool },
 }
 
@@ -1126,6 +1127,7 @@ fn create_event_from_stream_token(
     logprobs: bool,
     stream_options: Option<StreamOptions>,
     inner_using_tools: bool,
+    partial_call: Option<FunctionCallChunk>,
     system_fingerprint: String,
     model_id: String,
 ) -> Event {
@@ -1141,7 +1143,16 @@ fn create_event_from_stream_token(
 
     // replace the content with the tool calls if grammar is present
     let (content, tool_calls) = if inner_using_tools {
-        (None, Some(vec![stream_token.token.text.clone()]))
+        match partial_call {
+            Some(partial_call) => (None, Some(partial_call)),
+            None => (
+                None,
+                Some(FunctionCallChunk {
+                    name: None,
+                    arguments: stream_token.token.text.clone(),
+                }),
+            ),
+        }
     } else {
         let content = if !stream_token.token.special {
             Some(stream_token.token.text.clone())
@@ -1258,7 +1269,7 @@ pub(crate) async fn chat_completions(
             generate_stream_internal(infer, compute_type, Json(generate_request), span).await;
 
         // regex to match any function name
-        let function_regex = match Regex::new(r#"\{"function":\{"_name":"([^"]+)""#) {
+        let function_name_regex = match Regex::new(r#"\{"function":\{"_name":"([^"]+)","#) {
             Ok(regex) => regex,
             Err(e) => {
                 return Err((
@@ -1273,7 +1284,6 @@ pub(crate) async fn chat_completions(
 
         let response_stream = async_stream::stream! {
             let mut response_stream = Box::pin(response_stream);
-            let mut buffer = Vec::new();
             let mut json_buffer = String::new();
             let mut state = if using_tools {
                 StreamState::Buffering
@@ -1290,30 +1300,27 @@ pub(crate) async fn chat_completions(
                     match state {
                         StreamState::Buffering => {
                             json_buffer.push_str(&token_text.replace(" ", ""));
-                            buffer.push(stream_token);
-                            if let Some(captures) = function_regex.captures(&json_buffer) {
+                            if let Some(captures) = function_name_regex.captures(&json_buffer) {
                                 let function_name = captures[1].to_string();
                                 if function_name == "no_tool" {
                                     state = StreamState::BufferTrailing;
                                     response_as_tool = false;
-                                    buffer.clear();
                                     json_buffer.clear();
                                 } else {
-                                    state = StreamState::Content {
-                                        skip_close_quote: false,
-                                    };
-                                    // send all the buffered messages
-                                    for stream_token in &buffer {
-                                        let event = create_event_from_stream_token(
-                                            stream_token,
-                                            logprobs,
-                                            stream_options.clone(),
-                                            response_as_tool,
-                                            system_fingerprint.clone(),
-                                            model_id.clone(),
-                                        );
-                                        yield Ok::<Event, Infallible>(event);
-                                    }
+                                    state = StreamState::Arguments;
+                                    let event = create_event_from_stream_token(
+                                        &stream_token,
+                                        logprobs,
+                                        stream_options.clone(),
+                                        response_as_tool,
+                                        Some(FunctionCallChunk {
+                                            name: Some(function_name),
+                                            arguments: "{".to_string()
+                                        }),
+                                        system_fingerprint.clone(),
+                                        model_id.clone(),
+                                    );
+                                    yield Ok::<Event, Infallible>(event);
                                 }
                             }
                         }
@@ -1354,12 +1361,32 @@ pub(crate) async fn chat_completions(
                                 }));
                             }
                             // cleanup the buffers
-                            buffer.clear();
                             json_buffer.clear();
                             state = StreamState::Content {
                                 skip_close_quote: true,
                             };
                         }
+                        StreamState::Arguments => {
+                            json_buffer.push_str(&token_text.replace(" ", ""));
+
+                            // If we are at the end of the json we can stop
+                            let function: Result<serde::de::IgnoredAny, _> = serde_json::from_str(&json_buffer);
+                            if let Ok(_) = function {
+                                break;
+                            }
+
+                            // send the content
+                            let event = create_event_from_stream_token(
+                                &stream_token,
+                                logprobs,
+                                stream_options.clone(),
+                                response_as_tool,
+                                None,
+                                system_fingerprint.clone(),
+                                model_id.clone(),
+                            );
+                            yield Ok::<Event, Infallible>(event);
+                        }
                         StreamState::Content { skip_close_quote } => {
                             if skip_close_quote && token_text.contains('"') {
                                 break;
@@ -1371,6 +1398,7 @@ pub(crate) async fn chat_completions(
                                 logprobs,
                                 stream_options.clone(),
                                 response_as_tool,
+                                None,
                                 system_fingerprint.clone(),
                                 model_id.clone(),
                             );
@@ -1439,7 +1467,6 @@ pub(crate) async fn chat_completions(
                         id: "0".to_string(),
                         r#type: "function".to_string(),
                         function: FunctionCall {
-                            description: None,
                             name,
                             arguments: arguments.to_string(),
                         },
@@ -1572,7 +1599,6 @@ StreamOptions,
 DeltaToolCall,
 Tool,
 ToolCall,
-Function,
 FunctionDefinition,
 FunctionCall,
 ToolChoice,