sys.sql

-- get a list of stored procedures
select * from sys.procedures
-- get sproc parameters names
SELECT name
FROM sys.parameters
WHERE object_id = OBJECT_ID('sproc name')
-- get sproc parameters name, type, and length
SELECT p.name AS ParameterName, t.name AS ParameterType, p.max_length AS ParameterLength
FROM sys.parameters AS p
JOIN sys.types AS t ON t.user_type_id = p.user_type_id
WHERE object_id = OBJECT_ID('sproce name')