diff --git a/browse/src/server.ts b/browse/src/server.ts
index 2c6d7e0c..45266078 100644
--- a/browse/src/server.ts
+++ b/browse/src/server.ts
@@ -786,6 +786,27 @@ function killAgent(targetTabId?: number | null): void {
   agentStartTime = null;
   currentMessage = null;
   agentStatus = 'idle';
+  // Reset per-tab agent state too.  Without this, /sidebar-command on the
+  // same tab after a kill would see tabState.status === 'processing' (the
+  // legacy globals-only reset missed it) and fall into the queue branch
+  // instead of spawning.  When a specific tab was targeted, reset only
+  // that tab; otherwise reset ALL tabs (e.g. session-new kills everything).
+  if (targetTabId != null) {
+    const state = tabAgents.get(targetTabId);
+    if (state) {
+      state.status = 'idle';
+      state.startTime = null;
+      state.currentMessage = null;
+      state.queue = [];
+    }
+  } else {
+    for (const state of tabAgents.values()) {
+      state.status = 'idle';
+      state.startTime = null;
+      state.currentMessage = null;
+      state.queue = [];
+    }
+  }
 }
 
 // Agent health check — detect hung processes
diff --git a/browse/test/sidebar-integration.test.ts b/browse/test/sidebar-integration.test.ts
index bcafe052..d7a27fea 100644
--- a/browse/test/sidebar-integration.test.ts
+++ b/browse/test/sidebar-integration.test.ts
@@ -131,8 +131,12 @@ describe('sidebar-command → queue', () => {
     const lines = content.split('\n').filter(Boolean);
     expect(lines.length).toBeGreaterThan(0);
     const entry = JSON.parse(lines[lines.length - 1]);
+    // Active tab URL is carried on the queue entry metadata (entry.pageUrl),
+    // NOT inlined into the prompt.  The system prompt deliberately tells
+    // Claude to run `browse url` instead of trusting any URL in the prompt
+    // body — that's the prompt-injection-via-URL defense.  See spawnClaude
+    // in browse/src/server.ts.
     expect(entry.pageUrl).toBe('https://example.com/test-page');
-    expect(entry.prompt).toContain('https://example.com/test-page');
 
     await api('/sidebar-agent/kill', { method: 'POST' });
   });
@@ -185,12 +189,16 @@ describe('sidebar-agent/event → chat buffer', () => {
   test('agent events appear in /sidebar-chat', async () => {
     await resetState();
 
-    // Post mock agent events using Claude's streaming format
+    // Post pre-processed agent event.  The server's processAgentEvent
+    // handles the simplified types that sidebar-agent.ts emits (text,
+    // text_delta, tool_use, result, agent_error, security_event), NOT
+    // the raw Claude streaming format — pre-processing lives in
+    // sidebar-agent.ts, not in the server.
     await api('/sidebar-agent/event', {
       method: 'POST',
       body: JSON.stringify({
-        type: 'assistant',
-        message: { content: [{ type: 'text', text: 'Hello from mock agent' }] },
+        type: 'text',
+        text: 'Hello from mock agent',
       }),
     });