Avoidant Personality Disorder does not generaly impact on an individuals intellectual or physical capacities. In 'safe' familiar situations they will generally demonstrate no symptoms.
Job seeking can be very challenging because it triggers the individuals basic concerns. The individual will often have a great deal of difficulty effectively presenting their skills and qualifications. They will be awkward and uncomfortable in a job interview. An employer could easily discount the individuals abilities because of the manner in which they present themselves.
In employment they may have a great deal of trouble in new or changing situations. They will have trouble with interpersonal relationships and public speaking. They will tend to be perfectionists but downplay their skills, abilities and accomplishments. They will have a great deal of difficulty with any job that requires them to "sell" or even present their work to a potential customer, or even other co-workers.
Since their standard practice is to avoid situations that elicit their anxiety, they may just not attend important meetings, or be unable to participate in team discussions because they cannot allow themselves to feel part of a team.