diff --git a/openhands-tools/openhands/tools/terminal/constants.py b/openhands-tools/openhands/tools/terminal/constants.py
index b6cb4cc082..d8f6a33515 100644
--- a/openhands-tools/openhands/tools/terminal/constants.py
+++ b/openhands-tools/openhands/tools/terminal/constants.py
@@ -36,7 +36,9 @@
 
 TMUX_SOCKET_NAME: Final[str] = "openhands"
 
-# Tmux session dimensions (columns x rows).
-# Large values ensure output is not wrapped or truncated by the virtual terminal.
-TMUX_SESSION_WIDTH: Final[int] = 1000
-TMUX_SESSION_HEIGHT: Final[int] = 1000
+# Tmux session dimensions (columns x rows). Keep the viewport wide enough for
+# common command output while leaving scrollback retention to HISTORY_LIMIT.
+# Output wider than TMUX_SESSION_WIDTH columns will wrap; this is an accepted
+# tradeoff to avoid the oversized 1000x1000 virtual terminal grid.
+TMUX_SESSION_WIDTH: Final[int] = 256
+TMUX_SESSION_HEIGHT: Final[int] = 200
diff --git a/tests/tools/terminal/test_tmux_pane_pool.py b/tests/tools/terminal/test_tmux_pane_pool.py
index cb0ac610f0..5545d8b78a 100644
--- a/tests/tools/terminal/test_tmux_pane_pool.py
+++ b/tests/tools/terminal/test_tmux_pane_pool.py
@@ -6,9 +6,18 @@
 
 import pytest
 
+from openhands.tools.terminal.constants import (
+    TMUX_SESSION_HEIGHT,
+    TMUX_SESSION_WIDTH,
+)
 from openhands.tools.terminal.terminal.tmux_pane_pool import TmuxPanePool
 
 
+def test_tmux_session_viewport_is_bounded():
+    assert TMUX_SESSION_WIDTH <= 256
+    assert TMUX_SESSION_HEIGHT <= 200
+
+
 @pytest.fixture
 def pool():
     """Create and initialize a pool, close it after the test."""