argument "content" is null

mcp server:
@Tool(description = "获取当前日期")
public String getCurrentDate() {
return LocalDate.now().toString();
}

mcp client:
java.lang.IllegalStateException: Stream processing failed
at org.springframework.ai.chat.client.advisor.api.BaseAdvisor.lambda$adviseStream$2(BaseAdvisor.java:73) ~[spring-ai-client-chat-1.0.0.jar:1.0.0]
at reactor.core.publisher.FluxOnErrorResume$ResumeSubscriber.onError(FluxOnErrorResume.java:94) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxMap$MapSubscriber.onError(FluxMap.java:134) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.MonoFlatMapMany$FlatMapManyInner.onError(MonoFlatMapMany.java:256) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxContextWrite$ContextWriteSubscriber.onError(FluxContextWrite.java:121) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxDoFinally$DoFinallySubscriber.onError(FluxDoFinally.java:119) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxPeekFuseable$PeekConditionalSubscriber.onError(FluxPeekFuseable.java:903) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxMap$MapConditionalSubscriber.onError(FluxMap.java:265) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxPeekFuseable$PeekConditionalSubscriber.onError(FluxPeekFuseable.java:903) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxPeekFuseable$PeekConditionalSubscriber.onError(FluxPeekFuseable.java:903) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxPeekFuseable$PeekConditionalSubscriber.onError(FluxPeekFuseable.java:903) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxPeekFuseable$PeekConditionalSubscriber.onError(FluxPeekFuseable.java:903) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxHandle$HandleConditionalSubscriber.onError(FluxHandle.java:430) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxContextWrite$ContextWriteSubscriber.onError(FluxContextWrite.java:121) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxDoFinally$DoFinallySubscriber.onError(FluxDoFinally.java:119) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxPeekFuseable$PeekFuseableConditionalSubscriber.onError(FluxPeekFuseable.java:553) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxPublishOn$PublishOnConditionalSubscriber.doError(FluxPublishOn.java:1112) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxPublishOn$PublishOnConditionalSubscriber.checkTerminated(FluxPublishOn.java:1137) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxPublishOn$PublishOnConditionalSubscriber.runAsync(FluxPublishOn.java:996) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxPublishOn$PublishOnConditionalSubscriber.run(FluxPublishOn.java:1079) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.scheduler.WorkerTask.call(WorkerTask.java:84) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.scheduler.WorkerTask.call(WorkerTask.java:37) ~[reactor-core-3.7.7.jar:3.7.7]
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317) ~[na:na]
at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642) ~[na:na]
at java.base/java.lang.Thread.run(Thread.java:1583) ~[na:na]
Caused by: java.lang.RuntimeException: java.lang.IllegalArgumentException: argument "content" is null
at org.springframework.ai.model.ModelOptionsUtils.jsonToMap(ModelOptionsUtils.java:107) ~[spring-ai-model-1.0.0.jar:1.0.0]
at org.springframework.ai.model.ModelOptionsUtils.jsonToMap(ModelOptionsUtils.java:92) ~[spring-ai-model-1.0.0.jar:1.0.0]
at org.springframework.ai.mcp.SyncMcpToolCallback.call(SyncMcpToolCallback.java:113) ~[spring-ai-mcp-1.0.0.jar:1.0.0]
at org.springframework.ai.mcp.SyncMcpToolCallback.call(SyncMcpToolCallback.java:126) ~[spring-ai-mcp-1.0.0.jar:1.0.0]
at org.springframework.ai.model.tool.DefaultToolCallingManager.lambda$executeToolCall$5(DefaultToolCallingManager.java:224) ~[spring-ai-model-1.0.0.jar:1.0.0]
at io.micrometer.observation.Observation.observe(Observation.java:564) ~[micrometer-observation-1.15.1.jar:1.15.1]
at org.springframework.ai.model.tool.DefaultToolCallingManager.executeToolCall(DefaultToolCallingManager.java:221) ~[spring-ai-model-1.0.0.jar:1.0.0]
at org.springframework.ai.model.tool.DefaultToolCallingManager.executeToolCalls(DefaultToolCallingManager.java:137) ~[spring-ai-model-1.0.0.jar:1.0.0]
at org.springframework.ai.openai.OpenAiChatModel.lambda$internalStream$10(OpenAiChatModel.java:369) ~[spring-ai-openai-1.0.0.jar:1.0.0]
at reactor.core.publisher.FluxDefer.subscribe(FluxDefer.java:46) ~[reactor-core-3.7.7.jar:3.7.7]
at reactor.core.publisher.FluxSubscribeOn$SubscribeOnSubscriber.run(FluxSubscribeOn.java:194) ~[reactor-core-3.7.7.jar:3.7.7]
... 7 common frames omitted
Caused by: java.lang.IllegalArgumentException: argument "content" is null
at com.fasterxml.jackson.databind.ObjectMapper._assertNotNull(ObjectMapper.java:5126) ~[jackson-databind-2.19.1.jar:2.19.1]
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3869) ~[jackson-databind-2.19.1.jar:2.19.1]
at org.springframework.ai.model.ModelOptionsUtils.jsonToMap(ModelOptionsUtils.java:104) ~[spring-ai-model-1.0.0.jar:1.0.0]
... 17 common frames omitted

Start at SyncMcpToolCallback.call and ModelOptionsUtils.jsonToMap shown in the stack trace, then reproduce the Java MCP server/client tool call with the date tool. Done means the call completes without the null-content exception and the expected current-date result is returned.