chore: set default tool calling behaviour to be disabled (#3096)

Signed-off-by: ayushag <ayushag@nvidia.com>

lib/llm/src/preprocessor.rs

@@ -15,6 +15,7 @@ pub mod prompt;
 pub mod tools;
 
 use anyhow::Result;
+use dynamo_async_openai::types::ChatCompletionToolChoiceOption;
 use dynamo_async_openai::types::EncodingFormat;
 use futures::stream::{self, StreamExt};
 use prompt::OAIPromptFormatter;
@@ -77,6 +78,20 @@ pub struct JailState {
     finished: bool,                            // Add this flag to track if stream is finished
 }
 
+pub fn maybe_enable_tool_call(
+    parser_str: Option<&str>,
+    request: &NvCreateChatCompletionRequest,
+) -> bool {
+    // Enable tool call if the below two conditions are satisfied
+    // 1. parser_str is not None
+    // 2. tool_choice is not None
+    parser_str.is_some()
+        && !matches!(
+            request.inner.tool_choice,
+            Some(ChatCompletionToolChoiceOption::None)
+        )
+}
+
 impl LLMMetricAnnotation {
     /// Convert this metrics struct to an Annotated event
     pub fn to_annotation<T>(&self) -> Result<Annotated<T>, serde_json::Error> {
@@ -933,6 +948,8 @@ impl
         let response_generator = request.response_generator(context.id().to_string());
         let mut response_generator = Box::new(response_generator);
 
+        let enable_tool_calling =
+            maybe_enable_tool_call(self.tool_call_parser.as_deref(), &request);
         // convert the chat completion request to a common completion request
         let (common_request, annotations) = self.preprocess_request(&request)?;
 
@@ -955,7 +972,13 @@ impl
         // transform the postprocessor stream
         let stream = Self::transform_postprocessor_stream(response_stream, response_generator);
 
-        let stream = self.apply_tool_calling_jail_with_parser(stream).await;
+        // Apply tool calling jail to the stream if tool call parser is present
+        let stream = if enable_tool_calling {
+            self.apply_tool_calling_jail_with_parser(stream).await
+        } else {
+            stream
+        };
+
         let context = stream.context();
         // prepend the annotations to the response stream
         let stream = annotations_stream.chain(stream);

lib/llm/tests/test_preprocessor.rs

@@ -2,13 +2,18 @@
 // SPDX-License-Identifier: Apache-2.0
 
 use async_trait::async_trait;
+use dynamo_async_openai::types::ChatCompletionToolChoiceOption;
+use dynamo_async_openai::types::CreateChatCompletionRequest;
 use dynamo_async_openai::types::{
     ChatChoiceStream, ChatCompletionStreamResponseDelta, FinishReason as OAIFinishReason, Role,
 };
 use dynamo_llm::preprocessor::{
     ANNOTATION_POSSIBLE_TOOL_CALL, PossibleToolCallAnnotation, apply_tool_calling_jail_internal,
+    maybe_enable_tool_call,
+};
+use dynamo_llm::protocols::openai::chat_completions::{
+    NvCreateChatCompletionRequest, NvCreateChatCompletionStreamResponse,
 };
-use dynamo_llm::protocols::openai::chat_completions::NvCreateChatCompletionStreamResponse;
 use dynamo_parsers::tool_calling::parsers::detect_tool_call_start;
 use dynamo_runtime::pipeline::ResponseStream;
 use dynamo_runtime::protocols::annotated::Annotated;
@@ -709,3 +714,50 @@ async fn test_tool_calling_jail_internal_with_harmony_parser() {
     assert_eq!(name, "get_current_weather");
     assert_eq!(arguments["location"], "San Francisco");
 }
+
+#[test]
+fn test_enable_tool_call() {
+    let request = NvCreateChatCompletionRequest {
+        inner: CreateChatCompletionRequest {
+            tool_choice: Some(ChatCompletionToolChoiceOption::Auto),
+            ..Default::default()
+        },
+        common: Default::default(),
+        nvext: None,
+        chat_template_args: None,
+    };
+    assert!(maybe_enable_tool_call(Some("nemotron_deci"), &request));
+
+    let request = NvCreateChatCompletionRequest {
+        inner: CreateChatCompletionRequest {
+            tool_choice: Some(ChatCompletionToolChoiceOption::None),
+            ..Default::default()
+        },
+        common: Default::default(),
+        nvext: None,
+        chat_template_args: None,
+    };
+    assert!(!maybe_enable_tool_call(Some("nemotron_deci"), &request));
+
+    let request = NvCreateChatCompletionRequest {
+        inner: CreateChatCompletionRequest {
+            tool_choice: Some(ChatCompletionToolChoiceOption::Required),
+            ..Default::default()
+        },
+        common: Default::default(),
+        nvext: None,
+        chat_template_args: None,
+    };
+    assert!(maybe_enable_tool_call(Some("nemotron_deci"), &request));
+
+    let request = NvCreateChatCompletionRequest {
+        inner: CreateChatCompletionRequest {
+            tool_choice: Some(ChatCompletionToolChoiceOption::Auto),
+            ..Default::default()
+        },
+        common: Default::default(),
+        nvext: None,
+        chat_template_args: None,
+    };
+    assert!(!maybe_enable_tool_call(None, &request));
+}