phoenixToolChoiceSchema: ZodUnion<
    [
        ZodObject<
            { type: ZodLiteral<"none"> },
            "strip",
            ZodTypeAny,
            { type: "none" },
            { type: "none" },
        >,
        ZodObject<
            { type: ZodLiteral<"zero_or_more"> },
            "strip",
            ZodTypeAny,
            { type: "zero_or_more" },
            { type: "zero_or_more" },
        >,
        ZodObject<
            { type: ZodLiteral<"one_or_more"> },
            "strip",
            ZodTypeAny,
            { type: "one_or_more" },
            { type: "one_or_more" },
        >,
        ZodObject<
            { function_name: ZodString; type: ZodLiteral<"specific_function"> },
            "strip",
            ZodTypeAny,
            { function_name: string; type: "specific_function" },
            { function_name: string; type: "specific_function" },
        >,
    ],
> = ...

Phoenix's tool choice schema