diff --git a/src/agent/compactor.rs b/src/agent/compactor.rs
index ea2856b45..d308fd5dd 100644
--- a/src/agent/compactor.rs
+++ b/src/agent/compactor.rs
@@ -172,7 +172,24 @@ impl Compactor {
             return Ok(());
         }
 
-        let remove_count = total / 2;
+        let mut remove_count = total / 2;
+
+        // Advance past User messages containing ToolResult blocks so we never
+        // orphan tool_results whose matching tool_use was in a removed assistant
+        // message (the Anthropic API rejects orphaned tool_result blocks).
+        while remove_count < total.saturating_sub(2) {
+            let has_tool_result = matches!(
+                history.get(remove_count),
+                Some(Message::User { content })
+                    if content.iter().any(|item|
+                        matches!(item, UserContent::ToolResult(_)))
+            );
+            if has_tool_result {
+                remove_count += 1;
+            } else {
+                break;
+            }
+        }
 
         let removed: Vec<Message> = history.drain(..remove_count).collect();
         drop(removed);
@@ -206,12 +223,29 @@ async fn run_compaction(
     let (removed_messages, remove_count) = {
         let mut hist = history.write().await;
         let total = hist.len();
-        let remove_count = ((total as f32 * fraction) as usize)
+        let mut remove_count = ((total as f32 * fraction) as usize)
             .max(1)
             .min(total.saturating_sub(2));
         if remove_count == 0 {
             return Ok(0);
         }
+
+        // Advance past User messages containing ToolResult blocks so we never
+        // orphan tool_results whose matching tool_use was in a removed message.
+        while remove_count < total.saturating_sub(2) {
+            let has_tool_result = matches!(
+                hist.get(remove_count),
+                Some(Message::User { content })
+                    if content.iter().any(|item|
+                        matches!(item, UserContent::ToolResult(_)))
+            );
+            if has_tool_result {
+                remove_count += 1;
+            } else {
+                break;
+            }
+        }
+
         let removed: Vec<Message> = hist.drain(..remove_count).collect();
         (removed, remove_count)
     };
diff --git a/src/agent/worker.rs b/src/agent/worker.rs
index bfaf89170..dccf358df 100644
--- a/src/agent/worker.rs
+++ b/src/agent/worker.rs
@@ -746,9 +746,29 @@ impl Worker {
         let estimated = estimate_history_tokens(history);
         let usage = estimated as f32 / context_window as f32;
 
-        let remove_count = ((total as f32 * fraction) as usize)
+        let mut remove_count = ((total as f32 * fraction) as usize)
             .max(1)
             .min(total.saturating_sub(2));
+
+        // Advance the boundary past User messages that contain ToolResult blocks.
+        // If we stop right after an Assistant message with ToolCalls, the next
+        // User message holds the corresponding ToolResults. Leaving those orphaned
+        // causes the Anthropic API to reject the request with:
+        //   "unexpected tool_use_id found in tool_result blocks"
+        while remove_count < total.saturating_sub(2) {
+            let has_tool_result = matches!(
+                history.get(remove_count),
+                Some(rig::message::Message::User { content })
+                    if content.iter().any(|item|
+                        matches!(item, rig::message::UserContent::ToolResult(_)))
+            );
+            if has_tool_result {
+                remove_count += 1;
+            } else {
+                break;
+            }
+        }
+
         let removed: Vec<rig::message::Message> = history.drain(..remove_count).collect();
         compacted_history.extend(removed.iter().cloned());
 
diff --git a/src/config/types.rs b/src/config/types.rs
index 111f63238..9cce13984 100644
--- a/src/config/types.rs
+++ b/src/config/types.rs
@@ -842,7 +842,7 @@ impl Default for BrowserConfig {
         Self {
             enabled: true,
             headless: true,
-            evaluate_enabled: false,
+            evaluate_enabled: true,
             executable_path: None,
             screenshot_dir: None,
             persist_session: false,
diff --git a/src/tools/browser.rs b/src/tools/browser.rs
index e218131cc..378a4d818 100644
--- a/src/tools/browser.rs
+++ b/src/tools/browser.rs
@@ -2108,12 +2108,17 @@ impl Tool for BrowserCloseTool {
                     task.abort();
                 }
 
-                if let Some(mut browser) = browser
-                    && let Err(error) = browser.close().await
-                {
-                    let message = format!("failed to close browser: {error}");
-                    tracing::warn!(policy = "close_browser", %message);
-                    return Err(BrowserError::new(message));
+                if let Some(mut browser) = browser {
+                    if let Err(error) = browser.close().await {
+                        // The browser connection may already be dead (e.g. "oneshot canceled"
+                        // from a dropped WebSocket). That's fine — the browser is effectively
+                        // closed. Log it but don't fail the tool call.
+                        tracing::warn!(
+                            policy = "close_browser",
+                            %error,
+                            "browser.close() failed, treating as already closed"
+                        );
+                    }
                 }
 
                 if !persistent_profile && let Some(dir) = user_data_dir {