[BUG] [platform:intellij] NullPointerException in DiagnosticTools when HighlightInfo.getDescription() returns null

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

The Claude Code IntelliJ plugin (version 0.1.11-beta) crashes with a NullPointerException when processing code diagnostics via the MCP getDiagnostics tool. The error occurs in DiagnosticTools.kt at line 128 when HighlightInfo.getDescription() returns null.

Stack trace:

java.lang.NullPointerException: getDescription(...) must not be null
at com.anthropic.code.plugin.mcp.tools.DiagnosticTools$addTools$1$1$1.daemonFinished$lambda$0(DiagnosticTools.kt:128)
at com.anthropic.code.plugin.mcp.tools.DiagnosticTools$addTools$1$1$1.daemonFinished$lambda$1(DiagnosticTools.kt:118)
at com.intellij.codeInsight.daemon.impl.DaemonCodeAnalyzerEx.lambda$processHighlights$0(DaemonCodeAnalyzerEx.java:74)

The issue occurs because IntelliJ's HighlightInfo.getDescription() can legitimately return null for certain types of code highlights (structural highlighting, visual-only markers, etc.), but the plugin assumes it will always have a value.

What Should Happen?

The plugin should handle null descriptions gracefully by either:

1. Skipping highlights that don't have descriptions, or
2. Providing a default description like "<No description>"

This prevents crashes when processing diagnostics for files that contain highlights without textual descriptions.

Error Messages/Logs

java.lang.NullPointerException: getDescription(...) must not be null
	at com.anthropic.code.plugin.mcp.tools.DiagnosticTools$addTools$1$1$1.daemonFinished$lambda$0(DiagnosticTools.kt:128)
	at com.anthropic.code.plugin.mcp.tools.DiagnosticTools$addTools$1$1$1.daemonFinished$lambda$1(DiagnosticTools.kt:118)
	at com.intellij.codeInsight.daemon.impl.DaemonCodeAnalyzerEx.lambda$processHighlights$0(DaemonCodeAnalyzerEx.java:74)
	at com.intellij.util.containers.ContainerUtil.process(ContainerUtil.java:847)
	at com.intellij.openapi.editor.impl.MarkupModelImpl.processRangeHighlightersOverlappingWith(MarkupModelImpl.java:286)
	at com.intellij.codeInsight.daemon.impl.DaemonCodeAnalyzerEx.processHighlights(DaemonCodeAnalyzerEx.java:67)
	at com.intellij.codeInsight.daemon.impl.DaemonCodeAnalyzerEx.processHighlights(DaemonCodeAnalyzerEx.java:51)
	at com.anthropic.code.plugin.mcp.tools.DiagnosticTools$addTools$1$1$1.daemonFinished(DiagnosticTools.kt:112)
	at com.intellij.codeInsight.daemon.DaemonCodeAnalyzer$DaemonListener.daemonFinished(DaemonCodeAnalyzer.java:123)
	at com.intellij.util.messages.impl.MessageBusImplKt.invokeMethod(MessageBusImpl.kt:820)
	at com.intellij.util.messages.impl.MessageBusImplKt.invokeListener(MessageBusImpl.kt:764)
	at com.intellij.util.messages.impl.MessageBusImplKt.executeOrAddToQueue(MessageBusImpl.kt:585)
	at com.intellij.util.messages.impl.MessagePublisher.publish$intellij_platform_core(MessageBusImpl.kt:556)
	at com.intellij.util.messages.impl.MessagePublisher.invoke(MessageBusImpl.kt:533)
	at jdk.proxy2/jdk.proxy2.$Proxy86.daemonFinished(Unknown Source)
	at com.intellij.codeInsight.daemon.impl.DaemonCodeAnalyzerImpl$MyDaemonProgressIndicator.onStop(DaemonCodeAnalyzerImpl.java:1681)
	at com.intellij.codeInsight.daemon.impl.DaemonProgressIndicator.stop(DaemonProgressIndicator.java:39)
	at com.intellij.codeInsight.daemon.impl.PassExecutorService.lambda$applyInformationToEditorsLater$3(PassExecutorService.java:554)
	at com.intellij.openapi.application.TransactionGuardImpl.runWithWritingAllowed(TransactionGuardImpl.java:239)
	at com.intellij.openapi.application.TransactionGuardImpl.access$100(TransactionGuardImpl.java:25)
	at com.intellij.openapi.application.TransactionGuardImpl$1.run(TransactionGuardImpl.java:201)
	at com.intellij.openapi.application.impl.AppImplKt$runnableUnitFunction$1.invoke(appImpl.kt:124)
	at com.intellij.openapi.application.impl.AppImplKt$runnableUnitFunction$1.invoke(appImpl.kt:124)
	at com.intellij.platform.locking.impl.NestedLocksThreadingSupport.doRunWriteIntentReadAction(NestedLocksThreadingSupport.kt:717)
	at com.intellij.platform.locking.impl.NestedLocksThreadingSupport.runPreventiveWriteIntentReadAction(NestedLocksThreadingSupport.kt:691)
	at com.intellij.platform.locking.impl.NestedLocksThreadingSupport.runWriteIntentReadAction(NestedLocksThreadingSupport.kt:645)
	at com.intellij.openapi.application.impl.ApplicationImpl.runIntendedWriteActionOnCurrentThread(ApplicationImpl.java:1053)
	at com.intellij.openapi.application.impl.ApplicationImpl$6.lambda$run$0(ApplicationImpl.java:601)
	at com.intellij.concurrency.ThreadContext.installThreadContext(threadContext.kt:305)
	at com.intellij.openapi.application.impl.ApplicationImpl$6.run(ApplicationImpl.java:600)
	at com.intellij.util.concurrency.ChildContext$runInChildContext$1.invoke(propagation.kt:167)
	at com.intellij.util.concurrency.ChildContext$runInChildContext$1.invoke(propagation.kt:167)
	at com.intellij.util.concurrency.ChildContext.runInChildContext(propagation.kt:173)
	at com.intellij.util.concurrency.ChildContext.runInChildContext(propagation.kt:167)
	at com.intellij.util.concurrency.ContextRunnable.lambda$run$0(ContextRunnable.java:26)
	at com.intellij.concurrency.ThreadContext.resetThreadContext(threadContext.kt:294)
	at com.intellij.util.concurrency.ContextRunnable.run(ContextRunnable.java:25)
	at com.intellij.openapi.application.impl.FlushQueue.runNextEvent(FlushQueue.java:122)
	at com.intellij.openapi.application.impl.FlushQueue.lambda$flushNow$0(FlushQueue.java:42)
	at com.intellij.concurrency.ThreadContext.resetThreadContext(threadContext.kt:294)
	at com.intellij.openapi.application.impl.FlushQueue.flushNow(FlushQueue.java:30)
	at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:318)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:781)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:728)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:722)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:750)
	at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.kt:660)
	at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.kt:513)
	at com.intellij.ide.IdeEventQueue.dispatchEvent$lambda$0$0$0$0(IdeEventQueue.kt:333)
	at com.intellij.openapi.progress.impl.CoreProgressManager.computePrioritized(CoreProgressManager.java:896)
	at com.intellij.ide.IdeEventQueue.dispatchEvent$lambda$0$0$0(IdeEventQueue.kt:332)
	at com.intellij.ide.IdeEventQueueKt.performActivity$lambda$1(IdeEventQueue.kt:1061)
	at com.intellij.openapi.application.TransactionGuardImpl.performActivity(TransactionGuardImpl.java:109)
	at com.intellij.ide.IdeEventQueueKt.performActivity(IdeEventQueue.kt:1061)
	at com.intellij.ide.IdeEventQueue.dispatchEvent$lambda$0(IdeEventQueue.kt:327)
	at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.kt:367)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:207)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
	at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:92)

Steps to Reproduce

N/A

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.0

Platform

Claude Code Beta Intellij

Operating System

Other Linux

Terminal/Shell

IntelliJ IDEA terminal

Additional Information

_No response_