Hide empty MAINT slots from get_server_health output by default

Reduces MCP response from ~12.3k tokens (~1000 lines) to only active servers.
Empty pool slots (MAINT with no health check) are filtered by default.
Added show_all parameter to optionally show all slots.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/unit/tools/test_health.py

@@ -406,6 +406,93 @@ class TestHaproxyGetServerHealth:
 
         assert "No servers found" in result
 
+    def test_get_server_health_hides_empty_maint_slots(self, mock_socket_class, mock_select, patch_config_paths, response_builder):
+        """Empty MAINT slots (no health check) are hidden by default."""
+        mock_sock = mock_socket_class(responses={
+            "show stat": response_builder.stat_csv([
+                {"pxname": "pool_1", "svname": "pool_1_1", "status": "UP", "weight": 1, "check_status": "L4OK"},
+                {"pxname": "pool_1", "svname": "pool_1_2", "status": "MAINT", "weight": 1, "check_status": ""},
+                {"pxname": "pool_1", "svname": "pool_1_3", "status": "MAINT", "weight": 1, "check_status": ""},
+                {"pxname": "pool_2", "svname": "pool_2_1", "status": "MAINT", "weight": 1, "check_status": ""},
+            ]),
+        })
+
+        with patch("socket.socket", return_value=mock_sock):
+            from haproxy_mcp.tools.health import register_health_tools
+            mcp = MagicMock()
+            registered_tools = {}
+
+            def capture_tool():
+                def decorator(func):
+                    registered_tools[func.__name__] = func
+                    return func
+                return decorator
+
+            mcp.tool = capture_tool
+            register_health_tools(mcp)
+
+            result = registered_tools["haproxy_get_server_health"](backend="")
+
+        assert "pool_1_1" in result
+        assert "pool_1_2" not in result
+        assert "pool_1_3" not in result
+        assert "pool_2" not in result
+
+    def test_get_server_health_show_all_includes_empty_slots(self, mock_socket_class, mock_select, patch_config_paths, response_builder):
+        """show_all=True includes empty MAINT slots."""
+        mock_sock = mock_socket_class(responses={
+            "show stat": response_builder.stat_csv([
+                {"pxname": "pool_1", "svname": "pool_1_1", "status": "UP", "weight": 1, "check_status": "L4OK"},
+                {"pxname": "pool_1", "svname": "pool_1_2", "status": "MAINT", "weight": 1, "check_status": ""},
+            ]),
+        })
+
+        with patch("socket.socket", return_value=mock_sock):
+            from haproxy_mcp.tools.health import register_health_tools
+            mcp = MagicMock()
+            registered_tools = {}
+
+            def capture_tool():
+                def decorator(func):
+                    registered_tools[func.__name__] = func
+                    return func
+                return decorator
+
+            mcp.tool = capture_tool
+            register_health_tools(mcp)
+
+            result = registered_tools["haproxy_get_server_health"](backend="", show_all=True)
+
+        assert "pool_1_1" in result
+        assert "pool_1_2" in result
+
+    def test_get_server_health_keeps_maint_with_check(self, mock_socket_class, mock_select, patch_config_paths, response_builder):
+        """MAINT servers with health check status are kept (intentionally maintained)."""
+        mock_sock = mock_socket_class(responses={
+            "show stat": response_builder.stat_csv([
+                {"pxname": "pool_1", "svname": "pool_1_1", "status": "MAINT", "weight": 1, "check_status": "L4OK"},
+            ]),
+        })
+
+        with patch("socket.socket", return_value=mock_sock):
+            from haproxy_mcp.tools.health import register_health_tools
+            mcp = MagicMock()
+            registered_tools = {}
+
+            def capture_tool():
+                def decorator(func):
+                    registered_tools[func.__name__] = func
+                    return func
+                return decorator
+
+            mcp.tool = capture_tool
+            register_health_tools(mcp)
+
+            result = registered_tools["haproxy_get_server_health"](backend="")
+
+        assert "pool_1_1" in result
+        assert "MAINT" in result
+
     def test_get_server_health_haproxy_error(self, mock_socket_class, mock_select, patch_config_paths):
         """HAProxy error returns error message."""
         def raise_error(*args, **kwargs):