Insurance guidelines may differ from one insurance company to the next however speaking to your agent and informing them of an accident typically will not affect your rates. Many times your agent can advise you on if a claim should be filed, for instance if you were repairing your own vehicle and the claim is less then your deductible you would not end making a claim, and if a claim is to be filed the steps to take.
Usually a claim only affects premium when it is filed AND paid. Most claims loss reports are impacted ONLY after money is paid out. Or, if an accident is placed on your driving record then when your MVR is pulled and the accident is seen by your insurer it could affect your rates.
It is typically best to advise your agent of any accident you have been involved in so if a claim is filed they will be ready to take the claim. If you delay in advising your insurance carrier about an accident then you will need to inform them why there was a gap between time that the accident happening and when the file was placed with them.