sp_help_job returns information about jobs that are used by SQL Server Agent service to perform automated activities in SQL Server. When executed sp_help_job procedure with no parameters to return the information for all of the jobs currently defined in the msdb database.
SQL Server Agent is a Microsoft Windows service that executes scheduled administrative tasks, which are called jobs in SQL Server 2016. SQL Server Agent can run a job on a schedule, in response to a specific event, or on demand.
Here are few of the related blog posts.
Unable to start SQL ServerAgent – Failed to Initialize SQL Agent log
If you are unable to start the SQL AgentLog here is a good blog post which discusses about it.
SQLServerAgent is not currently running so it cannot be notified of this action
Getting error and finding the cause is something which I like. And off late over the blogs I have shared a number of such incidents that have helped me figure out stuffs all by myself. Of course, I do my research and more often than not make things complicated because there are a number of resolutions that I find.
Reference: Pinal Dave (http://blog.SQLAuthority.com)