When using Claude with Tools that dont have arguments, the eino tool component fails with "failed to unmarshal arguments in json" (empty string)

This happens cause the empty json string is stripped from the arguments.
https://github.com/cloudwego/eino-ext/blame/a2545a66f5cf63a9a582182fbff72bf752ec38c9/components/model/claude/claude.go#L625

This only happens when streaming and I understand why you removing the {}.

I dont really know where to fix this. But probably add here:
https://github.com/cloudwego/eino/blob/e17d69d5a166100226cd1213c9069879438a55d5/components/tool/utils/invokable_func.go#L135

a check like, if arguments == "" then arguments == "{}"