The journeyman seamer earned acclaim aged 36 in 2011 when he was an unlikely leading wicket-taker in Division One of the LV= County Championship.
Richardson’s 73 scalps helped Worcestershire, who were favourites for relegation, to stay in the top flight.
Worcestershire were a fifth county for Richardson, who began his career with Derbyshire in 1995 and also had a stint with minor county Staffordshire from 1996 to 1998.
He moved to Warwickshire in 1999 but had limited first-team opportunities and revitalised his career in 2005 by joining Middlesex.
Richardson claimed 57 first-class wickets in his debut season and further consistent performances earned a place on the 2008 England Lions tour of India where he took regular wickets.
His star waned somewhat and he turned down the offer of a player-coach's role at Middlesex to sign a two-year deal with Worcestershire from 2010.
That year his 55 championship wickets aided promotion and he went even better in 2011.