langchain/tools/json/tool.py/JsonSpec/from_file
class JsonSpec:    def from_file(cls, path: Path) -> JsonSpec:
        """Create a JsonSpec from a file."""
        if not path.exists():
            raise FileNotFoundError(f"File not found: {path}")
        dict_ = json.loads(path.read_text())
        return cls(dict_=dict_)