diff --git a/vllm/entrypoints/openai/chat_completion/serving.py b/vllm/entrypoints/openai/chat_completion/serving.py
index 2eb550c3e..ad7982b61 100644
--- a/vllm/entrypoints/openai/chat_completion/serving.py
+++ b/vllm/entrypoints/openai/chat_completion/serving.py
@@ -310,11 +310,14 @@ class OpenAIServingChat(OpenAIServing):
                     trace_headers=trace_headers,
                 )
             else:
-                reasoning_ended = (
-                    reasoning_parser.is_reasoning_end(prompt_token_ids or [])
-                    if reasoning_parser
-                    else None
-                )
+                if not request.include_reasoning:
+                    reasoning_ended = True
+                elif reasoning_parser:
+                    reasoning_ended = reasoning_parser.is_reasoning_end(
+                        prompt_token_ids or []
+                    )
+                else:
+                    reasoning_ended = None
 
                 generator = self.engine_client.generate(
                     engine_prompt,
diff --git a/vllm/tokenizers/mistral.py b/vllm/tokenizers/mistral.py
index ca61edeb8..e20f1edd4 100644
--- a/vllm/tokenizers/mistral.py
+++ b/vllm/tokenizers/mistral.py
@@ -15,8 +15,15 @@ from mistral_common.protocol.instruct.validator import ValidationMode
 from mistral_common.tokens.tokenizers.base import (
     SpecialTokenPolicy,
     SpecialTokens,
+    Tokenizer,
+)
+from mistral_common.tokens.tokenizers.instruct import (
+    InstructTokenizerBase,
+    InstructTokenizerV13,
+)
+from mistral_common.tokens.tokenizers.mistral import (
+    MistralTokenizer as MistralCommonTokenizer,
 )
-from mistral_common.tokens.tokenizers.instruct import InstructTokenizerV13
 from mistral_common.tokens.tokenizers.sentencepiece import (
     SentencePieceTokenizer,
 )
@@ -26,21 +33,20 @@ from pydantic import ValidationError
 from vllm.entrypoints.chat_utils import ChatCompletionMessageParam
 from vllm.entrypoints.openai.chat_completion.protocol import ChatCompletionRequest
 from vllm.logger import init_logger
+from vllm.tokenizers.protocol import TokenizerLike
 
-from .protocol import TokenizerLike
+try:
+    # Transformers v5
+    from transformers.tokenization_mistral_common import MistralCommonBackend
+except ImportError:
+    # Transformers v4
+    from transformers.tokenization_mistral_common import (
+        MistralCommonTokenizer as MistralCommonBackend,
+    )
 
 if TYPE_CHECKING:
     from transformers import BatchEncoding
 
-    try:
-        # Transformers v5
-        from transformers.tokenization_mistral_common import MistralCommonBackend
-    except ImportError:
-        # Transformers v4
-        from transformers.tokenization_mistral_common import (
-            MistralCommonTokenizer as MistralCommonBackend,
-        )
-
 logger = init_logger(__name__)
 
 
@@ -235,15 +241,6 @@ class MistralTokenizer(TokenizerLike):
         download_dir: str | None = None,
         **kwargs,
     ) -> "MistralTokenizer":
-        try:
-            # Transformers v5
-            from transformers.tokenization_mistral_common import MistralCommonBackend
-        except ImportError:
-            # Transformers v4
-            from transformers.tokenization_mistral_common import (
-                MistralCommonTokenizer as MistralCommonBackend,
-            )
-
         tokenizer = MistralCommonBackend.from_pretrained(
             path_or_repo_id,
             *args,
@@ -255,13 +252,13 @@ class MistralTokenizer(TokenizerLike):
 
         return cls(tokenizer)
 
-    def __init__(self, tokenizer: "MistralCommonBackend") -> None:
+    def __init__(self, tokenizer: MistralCommonBackend) -> None:
         super().__init__()
 
-        self.transformers_tokenizer = tokenizer
-        self.mistral = tokenizer.tokenizer
-        self.instruct = self.mistral.instruct_tokenizer
-        self.tokenizer = self.instruct.tokenizer
+        self.transformers_tokenizer: MistralCommonBackend = tokenizer
+        self.mistral: MistralCommonTokenizer = tokenizer.tokenizer
+        self.instruct: InstructTokenizerBase = self.mistral.instruct_tokenizer
+        self.tokenizer: Tokenizer = self.instruct.tokenizer
 
         mode = self.mistral._chat_completion_request_validator._mode
         if mode != ValidationMode.test:
@@ -483,7 +480,11 @@ class MistralTokenizer(TokenizerLike):
         return self.transformers_tokenizer.convert_tokens_to_ids(tokens)
 
     def convert_tokens_to_string(self, tokens: list[str]) -> str:
-        to_decode_special_tokens = {SpecialTokens.tool_calls}
+        to_decode_special_tokens = {
+            SpecialTokens.tool_calls,
+            SpecialTokens.begin_think,
+            SpecialTokens.end_think,
+        }
         if self.is_tekken:
             assert isinstance(self.tokenizer, Tekkenizer), type(self.tokenizer)
             tokens = [
diff --git a/vllm/tool_parsers/mistral_tool_parser.py b/vllm/tool_parsers/mistral_tool_parser.py
index baab4ade0..56ba245ce 100644
--- a/vllm/tool_parsers/mistral_tool_parser.py
+++ b/vllm/tool_parsers/mistral_tool_parser.py
@@ -241,7 +241,10 @@ class MistralToolParser(ToolParser):
         delta_token_ids: Sequence[int],
         request: ChatCompletionRequest,
     ) -> DeltaMessage | None:
-        if self.bot_token_id not in current_token_ids:
+        has_bot_token = (
+            self.bot_token_id in current_token_ids or self.bot_token in current_text
+        )
+        if not has_bot_token:
             # if the tool call token is not in the tokens generated so far,
             # append output to contents since it's not a tool
             return DeltaMessage(content=delta_text)
@@ -275,7 +278,8 @@ class MistralToolParser(ToolParser):
         additional_content: str = ""
         if self.streaming_state == StreamingState.WAITING_FOR_TOOL_START:
             # this is the first tool call
-            assert self.bot_token_id in delta_token_ids
+            if self.bot_token not in delta_text:
+                return DeltaMessage(content=delta_text)
             if not delta_text.startswith(self.bot_token):
                 additional_content += delta_text.split(self.bot_token)[0]
                 delta_text = self.bot_token + "".join(
@@ -411,7 +415,7 @@ class MistralToolParser(ToolParser):
             index=self.current_tool_id, type="function"
         )
         current_tool_call_modified = False
-        if self.bot_token_id in delta_token_ids:
+        if self.bot_token_id in delta_token_ids or self.bot_token in delta_text:
             # this is the first tool call
             if not delta_text.startswith(self.bot_token):
                 content = delta_text.split(self.bot_token)[0]