--字段添加说明
EXEC sp_addextendedproperty 'MS_Description', '要添加的说明', 'user', dbo, 'table', 表名, 'column', 列名
--删除字段说明
EXEC sp_dropextendedproperty 'MS_Description', 'user', dbo, 'table', 表名, 'column', 字段名
--查看字段说明
代码如下：

SELECT
[Table Name] = i_s.TABLE_NAME,
[Column Name] = i_s.COLUMN_NAME,
[Description] = s.value
FROM
INFORMATION_SCHEMA.COLUMNS i_s
LEFT OUTER JOIN
sysproperties s
ON
s.id = OBJECT_ID(i_s.TABLE_SCHEMA+'.'+i_s.TABLE_NAME)
AND s.smallid = i_s.ORDINAL_POSITION
AND s.name = 'MS_Description'
WHERE
OBJECTPROPERTY(OBJECT_ID(i_s.TABLE_SCHEMA+'.'+i_s.TABLE_NAME), 'IsMsShipped')=0
AND i_s.TABLE_NAME = 'jobs'
ORDER BY
i_s.TABLE_NAME, i_s.ORDINAL_POSITION