fix: Improved subagent escalation handling

src/function/mod.rs

@@ -186,42 +186,29 @@ pub async fn eval_tool_calls(
             })
             .collect();
         for (idx, call, result) in future::join_all(futs).await {
-            indexed_results.push((idx, ToolResult::new(call, normalize_tool_result(result?))));
+            let value = match result {
+                Ok(v) => normalize_tool_result(v),
+                Err(e) => json!({"tool_call_error": format!("{e}")}),
+            };
+            indexed_results.push((idx, ToolResult::new(call, value)));
         }
     }
 
     for (idx, call) in sequential_calls {
-        let result = call.eval(ctx).await?;
-        indexed_results.push((idx, ToolResult::new(call, normalize_tool_result(result))));
+        let value = match call.eval(ctx).await {
+            Ok(v) => normalize_tool_result(v),
+            Err(e) => json!({
+                "tool_call_error": format!(
+                    "{e}. This tool is not available or the call failed; use only tools listed in your catalog."
+                )
+            }),
+        };
+        indexed_results.push((idx, ToolResult::new(call, value)));
     }
 
     indexed_results.sort_unstable_by_key(|(idx, _)| *idx);
     output = indexed_results.into_iter().map(|(_, r)| r).collect();
 
-    if !output.is_empty() {
-        let (has_escalations, summary) = if ctx.current_depth == 0
-            && let Some(queue) = ctx.root_escalation_queue()
-            && queue.has_pending()
-        {
-            (true, queue.pending_summary())
-        } else {
-            (false, vec![])
-        };
-
-        if has_escalations {
-            let notification = json!({
-                "pending_escalations": summary,
-                "instruction": "Child agents are BLOCKED waiting for your reply. Call agent__reply_escalation for each pending escalation to unblock them."
-            });
-            let synthetic_call = ToolCall::new(
-                "__escalation_notification".to_string(),
-                json!({}),
-                Some("escalation_check".to_string()),
-            );
-            output.push(ToolResult::new(synthetic_call, notification));
-        }
-    }
-
     {
         let max_chars = ctx
             .agent
@@ -236,6 +223,14 @@ pub async fn eval_tool_calls(
         }
     }
 
+    if ctx.current_depth == 0
+        && let Some(queue) = ctx.root_escalation_queue()
+        && queue.has_pending()
+        && let Some(last) = output.last_mut()
+    {
+        inject_escalation_notification(last, queue.pending_summary());
+    }
+
     Ok(output)
 }
 
@@ -252,6 +247,24 @@ fn normalize_tool_result(result: Value) -> Value {
     }
 }
 
+fn inject_escalation_notification(last: &mut ToolResult, summary: Vec<Value>) {
+    let instruction = "Child agents are BLOCKED waiting for your reply. \
+        Call agent__reply_escalation for each pending escalation to unblock them.";
+    match &mut last.output {
+        Value::Object(map) => {
+            map.insert("pending_escalations".into(), json!(summary));
+            map.insert("escalation_instruction".into(), json!(instruction));
+        }
+        other => {
+            *other = json!({
+                "output": other.take(),
+                "pending_escalations": summary,
+                "escalation_instruction": instruction,
+            });
+        }
+    }
+}
+
 #[derive(Debug, Clone, Deserialize, Serialize)]
 pub struct ToolResult {
     pub call: ToolCall,
@@ -1741,7 +1754,10 @@ fn format_json_colored_keys(value: &serde_json::Value) -> String {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::config::{AppState, WorkingMode};
+    use crate::supervisor::escalation::{EscalationQueue, EscalationRequest};
     use serde_json::json;
+    use std::sync::Arc;
 
     fn call(name: &str, id: Option<&str>) -> ToolCall {
         ToolCall::new(name.to_string(), json!({}), id.map(|s| s.to_string()))
@@ -1751,11 +1767,98 @@ mod tests {
         ToolCall::new(name.to_string(), args, Some("id1".to_string()))
     }
 
+    fn run_async<F: Future>(f: F) -> F::Output {
+        tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()
+            .unwrap()
+            .block_on(f)
+    }
+
+    fn submit_escalation(queue: &EscalationQueue, id: &str) {
+        let (tx, _rx) = tokio::sync::oneshot::channel();
+        queue.submit(EscalationRequest {
+            id: id.to_string(),
+            from_agent_id: "a1".into(),
+            from_agent_name: "explore".into(),
+            question: "What do?".into(),
+            options: None,
+            reply_tx: tx,
+        });
+    }
+
     #[test]
     fn normalize_tool_result_substitutes_done_for_null() {
         assert_eq!(normalize_tool_result(Value::Null), json!("DONE"));
     }
 
+    #[test]
+    fn inject_escalation_notification_extends_object_output() {
+        let mut result = ToolResult::new(call("t", Some("id-1")), json!({"status": "ok"}));
+        inject_escalation_notification(&mut result, vec![json!({"escalation_id": "esc_1"})]);
+        assert_eq!(result.output["status"], "ok");
+        assert_eq!(
+            result.output["pending_escalations"],
+            json!([{"escalation_id": "esc_1"}])
+        );
+        assert!(
+            result.output["escalation_instruction"]
+                .as_str()
+                .unwrap()
+                .contains("agent__reply_escalation")
+        );
+        assert!(result.text.is_none());
+    }
+
+    #[test]
+    fn inject_escalation_notification_wraps_non_object_output() {
+        let mut result = ToolResult::new(call("t", Some("id-1")), json!("DONE"));
+        inject_escalation_notification(&mut result, vec![json!({"escalation_id": "esc_2"})]);
+        assert_eq!(result.output["output"], json!("DONE"));
+        assert_eq!(
+            result.output["pending_escalations"],
+            json!([{"escalation_id": "esc_2"}])
+        );
+        assert!(result.output["escalation_instruction"].is_string());
+    }
+
+    #[test]
+    fn eval_tool_calls_soft_fails_unknown_tool() {
+        let mut ctx = RequestContext::new(Arc::new(AppState::test_default()), WorkingMode::Cmd);
+        let calls = vec![call("__escalation_notification", Some("id-1"))];
+        let results = run_async(eval_tool_calls(&mut ctx, calls)).unwrap();
+        assert_eq!(results.len(), 1);
+        let err = results[0].output["tool_call_error"].as_str().unwrap();
+        assert!(err.contains("Unexpected call"));
+        assert!(err.contains("use only tools listed in your catalog"));
+    }
+
+    #[test]
+    fn eval_tool_calls_injects_escalations_into_last_result() {
+        let mut ctx = RequestContext::new(Arc::new(AppState::test_default()), WorkingMode::Cmd);
+        let queue = ctx.ensure_root_escalation_queue();
+        submit_escalation(&queue, "esc_1");
+
+        let calls = vec![call("unknown_tool", Some("id-1"))];
+        let results = run_async(eval_tool_calls(&mut ctx, calls)).unwrap();
+
+        assert_eq!(results.len(), 1);
+        assert!(
+            results
+                .iter()
+                .all(|r| r.call.name != "__escalation_notification")
+        );
+        let out = &results[0].output;
+        assert!(out["tool_call_error"].is_string());
+        assert_eq!(out["pending_escalations"][0]["escalation_id"], "esc_1");
+        assert!(
+            out["escalation_instruction"]
+                .as_str()
+                .unwrap()
+                .contains("agent__reply_escalation")
+        );
+    }
+
     #[test]
     fn normalize_tool_result_preserves_non_null_values() {
         assert_eq!(