feat: add Tip section to Slack trace-reply initial message (#1268)

Co-authored-by: open-swe[bot] <open-swe@users.noreply.github.com>

agent/utils/slack.py

@@ -610,6 +610,24 @@ TRACE_REPLY_PHRASES: tuple[str, ...] = (
     "Running to the roar!",
 )
 
+TRACE_REPLY_TIPS: tuple[str, ...] = (
+    "You can message me in this thread while I'm running — I'll pick up your follow-up before my next step.",
+    "Kick off another task in parallel — each one runs in its own isolated sandbox, no queuing.",
+    "Add `repo:owner/name` to your message to point me at a different repo for this task.",
+    "Drop an `AGENTS.md` at your repo root and I'll read it on every run — it's the easiest way to teach me your conventions.",
+    "I'll open a draft PR automatically when I'm done and link it back here.",
+    "Tag me on a PR comment of an open-swe PR to have me address review feedback on the same branch.",
+    "I can spawn subagents for independent subtasks — useful for parallel research or fan-out work.",
+    "Click `View trace` above to watch every tool call and model response live in LangSmith.",
+)
+
+
+def _format_trace_reply(message: str, trace_url: str | None) -> str:
+    """Format the initial trace reply with a randomly selected tip."""
+    tip = random.choice(TRACE_REPLY_TIPS)
+    head = f"{message} <{trace_url}|View trace>" if trace_url else message
+    return f"{head}\n_Tip: {tip}_"
+
 
 async def post_slack_trace_reply(
     channel_id: str, thread_ts: str, thread_id: str, message: str | None = None
@@ -618,7 +636,4 @@ async def post_slack_trace_reply(
     if message is None:
         message = random.choice(TRACE_REPLY_PHRASES)
     trace_url = get_langsmith_trace_url(thread_id)
-    if trace_url:
+    await post_slack_thread_reply(channel_id, thread_ts, _format_trace_reply(message, trace_url))
-        await post_slack_thread_reply(channel_id, thread_ts, f"{message} <{trace_url}|View trace>")
-    else:
-        await post_slack_thread_reply(channel_id, thread_ts, message)

tests/test_slack_context.py

@@ -6,6 +6,7 @@ from agent import webapp
 from agent.utils import slack as slack_utils
 from agent.utils.slack import (
     TRACE_REPLY_PHRASES,
+    TRACE_REPLY_TIPS,
     convert_mentions_to_slack_format,
     format_slack_messages_for_prompt,
     looks_like_slack_pr_review_command,
@@ -235,7 +236,10 @@ def test_post_slack_trace_reply_picks_random_phrase_when_no_message(
     asyncio.run(post_slack_trace_reply("C123", "1.0", "thread-id"))
 
     assert len(posted) == 1
-    assert posted[0] in TRACE_REPLY_PHRASES
+    head, _, tip_line = posted[0].partition("\n")
+    assert head in TRACE_REPLY_PHRASES
+    assert tip_line.startswith("_Tip: ") and tip_line.endswith("_")
+    assert any(tip in tip_line for tip in TRACE_REPLY_TIPS)
 
 
 def test_post_slack_trace_reply_uses_explicit_message_when_provided(
@@ -251,7 +255,11 @@ def test_post_slack_trace_reply_uses_explicit_message_when_provided(
 
     asyncio.run(post_slack_trace_reply("C123", "1.0", "thread-id", message="Taking a look..."))
 
-    assert posted == ["Taking a look..."]
+    assert len(posted) == 1
+    head, _, tip_line = posted[0].partition("\n")
+    assert head == "Taking a look..."
+    assert tip_line.startswith("_Tip: ") and tip_line.endswith("_")
+    assert any(tip in tip_line for tip in TRACE_REPLY_TIPS)
 
 
 def test_select_slack_context_messages_detects_username_mention() -> None: