chore: minor check refactoring for bedrock messages tool use stream chunk transform

Author: VisargD

src/providers/bedrock/messages.ts

@@ -548,12 +548,12 @@ export const BedrockConverseMessagesStreamChunkTransform = (
     const contentBlockStartEvent: RawContentBlockStartEvent = JSON.parse(
       ANTHROPIC_CONTENT_BLOCK_START_EVENT
     );
-    if (parsedChunk.start?.toolUse) {
+    if (parsedChunk.start?.toolUse && parsedChunk.start.toolUse.toolUseId) {
       contentBlockStartEvent.content_block = {
         type: 'tool_use',
         id: parsedChunk.start.toolUse.toolUseId,
         name: parsedChunk.start.toolUse.name,
-        input: parsedChunk.start.toolUse.input || {},
+        input: {},
       };
     }
     contentBlockStartEvent.index = parsedChunk.contentBlockIndex;