If the answer is yes then as a landlord you have done the necessary checks.
The contractor should provide;
An electrical report (EICR) or and electrical certificate (EIC / EICR) for the works carried out
A smoke detector certificate (mains powered to BS5839:Pt6)
Instructions for items installed
The paperwork (if correct and provided by a competent person) reduces the liability on the landlord significantly - if something were to happen a landlord could point to a SATISFACTORY electrical certificate from a competent person or company.
This goes a long way (legally) to prove the landlord took all reasonable steps with regards to electrical safety.
It is good to have pdf versions as these can be given to the tenant via email.