chore: import upstream snapshot with attribution

entity/tool_spec.py

@@ -0,0 +1,31 @@
+"""Provider-agnostic tool specification dataclasses."""
+
+from dataclasses import dataclass, field
+from typing import Any, Dict
+
+
+@dataclass
+class ToolSpec:
+    """Generic representation of a callable tool."""
+
+    name: str
+    description: str = ""
+    parameters: Dict[str, Any] = field(default_factory=dict)
+    metadata: Dict[str, Any] = field(default_factory=dict)
+
+    def to_openai_dict(self) -> Dict[str, Any]:
+        """Convert to OpenAI Responses API function schema."""
+        return {
+            "type": "function",
+            "name": self.name,
+            "description": self.description,
+            "parameters": self.parameters or {"type": "object", "properties": {}},
+        }
+
+    def to_gemini_function(self) -> Dict[str, Any]:
+        """Convert to Gemini FunctionDeclaration schema."""
+        return {
+            "name": self.name,
+            "description": self.description,
+            "parameters": self.parameters or {"type": "object", "properties": {}},
+        }