diff --git a/vllm/tool_parsers/qwen3coder_tool_parser.py b/vllm/tool_parsers/qwen3coder_tool_parser.py
index 216ae163b77a..e4b09bed1e71 100644
--- a/vllm/tool_parsers/qwen3coder_tool_parser.py
+++ b/vllm/tool_parsers/qwen3coder_tool_parser.py
@@ -157,12 +157,16 @@ def _convert_param_value(
             and "type" in param_config[param_name]
         ):
             param_type = str(param_config[param_name]["type"]).strip().lower()
-        elif (
-            isinstance(param_config[param_name], dict)
-            and "anyOf" in param_config[param_name]
+        elif isinstance(param_config[param_name], dict) and (
+            "anyOf" in param_config[param_name]
         ):
             # anyOf has no top-level "type"; treat as object to trigger json.loads.
             param_type = "object"
+        elif isinstance(param_config[param_name], dict) and (
+            "$ref" in param_config[param_name]
+        ):
+            # $ref has no type information at this level; treat it separately.
+            param_type = "$ref"
         else:
             param_type = "string"
         if param_type in ["string", "str", "text", "varchar", "char", "enum"]:
@@ -214,6 +218,24 @@ def _convert_param_value(
                     func_name,
                 )
             return param_value == "true"
+        elif param_type == "$ref":
+            # For $ref types, we don't have direct type information here.
+            # Attempt JSON parsing first, then fallback to string.
+            # We avoid ast.literal_eval for $ref types due to potential complexity and
+            # security concerns.
+            try:
+                param_value = json.loads(param_value)
+                return param_value
+            except (json.JSONDecodeError, TypeError, ValueError):
+                logger.debug(
+                    "Parsed value '%s' of parameter '%s' cannot be "
+                    "parsed with json.loads for $ref type in tool '%s', "
+                    "degenerating to string.",
+                    param_value,
+                    param_name,
+                    func_name,
+                )
+                return param_value
         else:
             if (
                 param_type in ["object", "array", "arr"]