diff --git a/changes/485.fixed.md b/changes/485.fixed.md
new file mode 100644
index 000000000..3edb8a64e
--- /dev/null
+++ b/changes/485.fixed.md
@@ -0,0 +1,2 @@
+**Activity shows what a chat tool was given on Windows again.** A line like "query: Saturday plans" could be missing
+under a tool Sentient used in a chat, because two messages saved in the same instant got mixed up.
diff --git a/sentient/activity/timeline.py b/sentient/activity/timeline.py
index c40bd04a9..b4b5164ec 100644
--- a/sentient/activity/timeline.py
+++ b/sentient/activity/timeline.py
@@ -335,10 +335,12 @@ def _chat_item(self, row: Any) -> Item:
                     app_label=label, ref=ref, undo=undo, _args=args, _apps=also)
 
     async def _call_arguments(self, session_id: str, call_id: str, at: str) -> dict | None:
-        """The arguments a chat tool call was given, read from the assistant message that made it."""
+        """The arguments a chat tool call was given, read from the assistant message that made it. Found by the call's
+        id: Windows' clock can give a tool result and the next call the same ``created_at`` (#485)."""
         row = await self.store.fetchone(
             "SELECT tool_calls FROM messages WHERE session_id = ? AND role = 'assistant' AND created_at <= ?"
-            " AND tool_calls IS NOT NULL ORDER BY created_at DESC LIMIT 1", (session_id, at),
+            " AND tool_calls IS NOT NULL AND instr(tool_calls, ?) > 0 ORDER BY created_at DESC LIMIT 1",
+            (session_id, at, json.dumps(call_id)),  # quoted and escaped as stored; the loop below checks the id
         )
         calls = _loads(row["tool_calls"]) if row else None
         for call in calls if isinstance(calls, list) else []:
diff --git a/tests/test_claude_code.py b/tests/test_claude_code.py
index 8ae39af23..988f70ee9 100644
--- a/tests/test_claude_code.py
+++ b/tests/test_claude_code.py
@@ -822,8 +822,8 @@ async def one() -> str:
         return await llm.complete_text("fast", [{"role": "user", "content": "hi"}])
 
     first = asyncio.create_task(one())
-    for _ in range(300):
-        if claude_code._live:
+    for _ in range(300):  # running and logged, not just spawned: slow to start on Windows (claude.cmd, then Python)
+        if claude_code._live and fake_claude.runs():
             break
         await asyncio.sleep(0.05)
     second = asyncio.create_task(one())
diff --git a/tests/test_timeline.py b/tests/test_timeline.py
index a81292035..ac19feb49 100644
--- a/tests/test_timeline.py
+++ b/tests/test_timeline.py
@@ -106,6 +106,19 @@ async def _all(s: SentientApp, **kw) -> list[dict]:
     raise AssertionError("paging never ended")
 
 
+async def test_a_call_id_that_json_escapes_is_still_found(config, isolated_home):
+    s = await _app(config, isolated_home)
+    try:
+        sid = await s.store.create_session(channel="web", title="Trip")
+        call = {"id": "call_é1", "type": "function",
+                "function": {"name": "mail_search", "arguments": json.dumps({"query": "Goa"})}}
+        await s.store.add_message(sid, "assistant", "", tool_calls=[call])
+        row = await s.store.fetchone("SELECT created_at FROM messages WHERE session_id = ?", (sid,))
+        assert await s.timeline._call_arguments(sid, "call_é1", row["created_at"]) == {"query": "Goa"}
+    finally:
+        await s.stop()
+
+
 async def test_chat_tool_calls_and_approvals_say_what_and_why(config, isolated_home):
     sent: list[str] = []
     llm = FakeProvider(replies=[
@@ -147,6 +160,32 @@ async def test_chat_tool_calls_and_approvals_say_what_and_why(config, isolated_h
         await s.stop()
 
 
+async def test_a_calls_details_survive_a_shared_timestamp(config, isolated_home):
+    # Windows' clock (Python 3.12) ticks every 15.6 ms: a tool result and the next call often share created_at
+    s = await _app(config, isolated_home)
+    try:
+        sid = await s.store.create_session(channel="web", title="Weekend plans")
+        search = {"id": "c1", "type": "function",
+                  "function": {"name": "mail_search", "arguments": json.dumps({"query": "Saturday plans"})}}
+        send = {"id": "c2", "type": "function",  # its arguments mention c1, the way a reply to it might
+                "function": {"name": "mail_send", "arguments": json.dumps({"to": "Arjun", "body": "re c1",
+                                                                           "ref": "c1"})}}
+        await s.store.add_message(sid, "assistant", "", tool_calls=[search])
+        await s.store.add_message(sid, "tool", json.dumps({"results": []}), tool_call_id="c1", name="mail_search")
+        await s.store.add_message(sid, "assistant", "", tool_calls=[send])
+        # c1 is asked a tick earlier; its result and the next call (c2) land in the same tick
+        at = "2026-10-20T10:00:00+00:00"
+        await s.store.execute("UPDATE messages SET created_at = ? WHERE session_id = ?", (at, sid))
+        await s.store.execute(
+            "UPDATE messages SET created_at = ? WHERE session_id = ? AND instr(tool_calls, 'mail_search') > 0",
+            ("2026-10-20T09:59:59.984000+00:00", sid),
+        )
+        assert await s.timeline._call_arguments(sid, "c1", at) == {"query": "Saturday plans"}
+        assert await s.timeline._call_arguments(sid, "c2", at) == {"to": "Arjun", "body": "re c1", "ref": "c1"}
+    finally:
+        await s.stop()
+
+
 async def test_incognito_chats_never_show(config, isolated_home):
     s = await _app(config, isolated_home, FakeProvider(replies=[[tool_call("mail_search", query="secret")], "ok"]))
     try: