diff --git a/src/core/assistant-message/NativeToolCallParser.ts b/src/core/assistant-message/NativeToolCallParser.ts
index 72c34f94a0..c8d9d471a6 100644
--- a/src/core/assistant-message/NativeToolCallParser.ts
+++ b/src/core/assistant-message/NativeToolCallParser.ts
@@ -166,16 +166,27 @@ export class NativeToolCallParser {
 	/**
 	 * Process stream finish reason.
 	 * Emits end events when finish_reason is 'tool_calls'.
+	 * Only emits events for tool calls that have been properly started (have a name).
 	 */
 	public static processFinishReason(finishReason: string | null | undefined): ToolCallStreamEvent[] {
 		const events: ToolCallStreamEvent[] = []
 
 		if (finishReason === "tool_calls" && this.rawChunkTracker.size > 0) {
 			for (const [, tracked] of this.rawChunkTracker.entries()) {
-				events.push({
-					type: "tool_call_end",
-					id: tracked.id,
-				})
+				// Only emit end event if the tool call was properly started
+				// (i.e., we received a name and emitted tool_call_start)
+				if (tracked.hasStarted) {
+					events.push({
+						type: "tool_call_end",
+						id: tracked.id,
+					})
+				} else {
+					// Log diagnostic warning for unstarted tool calls
+					console.warn(
+						`[NativeToolCallParser] Skipping tool_call_end for unstarted tool call: ${tracked.id} ` +
+							`(no name received, hasStarted=false)`,
+					)
+				}
 			}
 		}
 
diff --git a/src/core/assistant-message/__tests__/NativeToolCallParser.spec.ts b/src/core/assistant-message/__tests__/NativeToolCallParser.spec.ts
index db0dc00de4..4a95b23a87 100644
--- a/src/core/assistant-message/__tests__/NativeToolCallParser.spec.ts
+++ b/src/core/assistant-message/__tests__/NativeToolCallParser.spec.ts
@@ -343,4 +343,122 @@ describe("NativeToolCallParser", () => {
 			})
 		})
 	})
+
+	describe("processFinishReason", () => {
+		describe("hasStarted check", () => {
+			it("should emit tool_call_end for started tool calls", () => {
+				// Simulate a tool call that has been properly started
+				NativeToolCallParser.processRawChunk({
+					index: 0,
+					id: "call_started",
+					name: "read_file",
+					arguments: '{"path":"test.ts"}',
+				})
+
+				const events = NativeToolCallParser.processFinishReason("tool_calls")
+
+				expect(events).toHaveLength(1)
+				expect(events[0]).toEqual({
+					type: "tool_call_end",
+					id: "call_started",
+				})
+			})
+
+			it("should NOT emit tool_call_end for unstarted tool calls", () => {
+				// Simulate a tool call that received an ID but no name (not started)
+				NativeToolCallParser.processRawChunk({
+					index: 0,
+					id: "call_unstarted",
+					// No name provided - tool call is tracked but not started
+				})
+
+				const events = NativeToolCallParser.processFinishReason("tool_calls")
+
+				// Should not emit any events because the tool call wasn't started
+				expect(events).toHaveLength(0)
+			})
+
+			it("should handle mixed started and unstarted tool calls", () => {
+				// First tool call: properly started
+				NativeToolCallParser.processRawChunk({
+					index: 0,
+					id: "call_started_1",
+					name: "read_file",
+					arguments: '{"path":"test1.ts"}',
+				})
+
+				// Second tool call: tracked but not started (no name)
+				NativeToolCallParser.processRawChunk({
+					index: 1,
+					id: "call_unstarted",
+					// No name - won't be started
+				})
+
+				// Third tool call: properly started
+				NativeToolCallParser.processRawChunk({
+					index: 2,
+					id: "call_started_2",
+					name: "write_to_file",
+					arguments: '{"path":"output.ts"}',
+				})
+
+				const events = NativeToolCallParser.processFinishReason("tool_calls")
+
+				// Should only emit end events for the two started tool calls
+				expect(events).toHaveLength(2)
+				expect(events[0]).toEqual({
+					type: "tool_call_end",
+					id: "call_started_1",
+				})
+				expect(events[1]).toEqual({
+					type: "tool_call_end",
+					id: "call_started_2",
+				})
+			})
+
+			it("should not emit events when finish_reason is not tool_calls", () => {
+				// Set up a started tool call
+				NativeToolCallParser.processRawChunk({
+					index: 0,
+					id: "call_started",
+					name: "read_file",
+					arguments: '{"path":"test.ts"}',
+				})
+
+				// Process with different finish reason
+				const events = NativeToolCallParser.processFinishReason("stop")
+
+				expect(events).toHaveLength(0)
+			})
+
+			it("should handle tool call that receives name in a separate chunk", () => {
+				// First chunk: ID only
+				NativeToolCallParser.processRawChunk({
+					index: 0,
+					id: "call_delayed_name",
+				})
+
+				// At this point, tool call is tracked but not started
+				let events = NativeToolCallParser.processFinishReason("tool_calls")
+				expect(events).toHaveLength(0)
+
+				// Clear state and try again with name
+				NativeToolCallParser.clearRawChunkState()
+
+				// Simulate proper sequence with name
+				NativeToolCallParser.processRawChunk({
+					index: 0,
+					id: "call_delayed_name",
+					name: "read_file",
+				})
+
+				events = NativeToolCallParser.processFinishReason("tool_calls")
+				expect(events).toHaveLength(1)
+				expect(events[0]).toEqual({
+					type: "tool_call_end",
+					id: "call_delayed_name",
+				})
+			})
+		})
+	})
 })