Alarm dog, yes; guard dog, no
If by watchdog you mean a dog that notices everything and tells you about it loudly, a German Shorthaired Pointer does the job well. Pointers are alert, environmentally aware dogs with a hunter's habit of scanning movement, and most will bark at a car pulling in, footsteps on the path, or a stranger at the fence. The bark is substantial, the dog behind it is large and athletic, and that alone discourages most opportunists.
If by watchdog you mean a dog that will confront or deter an intruder who keeps coming, this is the wrong breed. The pointer's default setting with unfamiliar people is sociability, not suspicion. Many would greet a burglar enthusiastically and show them where the valuables are kept, possibly carrying one themselves. Breeds developed for guarding were selected for territorial suspicion over generations; pointers were selected for the opposite, working cooperatively among strangers and strange dogs all day.
What a pointer's territorial behavior actually looks like
Most pointers are watchful about the home's perimeter in an informational way. They track passers-by from windows, alert to unusual sounds at night, and investigate new objects in the garden with intense interest. That vigilance comes from the same awareness that makes them read a field for birds, and it tends to increase as the dog matures out of puppyhood.
What you should not see is escalating aggression: hard staring, raised hackles with a stiff body, growling that intensifies as people retreat, or guarding doors against household members. In this breed those signs point to fear or poor socialization rather than good watchdog instinct, and they need professional help, not praise. Encouraging a strong sporting dog to be suspicious of visitors is genuinely dangerous and can end with a dog that cannot safely live in a normal social household.
Managing the barking side of the bargain
The practical problem with a pointer watchdog is usually volume management. A dog bred to notice everything will also announce squirrels, delivery vans, the neighbor's cat, and leaves with opinions. Owners do best teaching a clear job description: bark to alert, then a trained quiet and a recall to you once you have acknowledged the event. Reward the dog for reporting, take over the situation visibly, and the barking has an ending.
Under-exercise inflates the problem. A pointer with unspent energy patrols windows for entertainment, so a dog that barks at everything all afternoon is often telling you about its morning, not about genuine threats. More work, more training, and a resting place away from the front window usually cut nuisance barking far more than any correction.
If security is a real priority
Choose honestly. If your property genuinely needs a deterrent presence, pair a pointer's alarm with locks, lighting, and an actual security system rather than asking the dog to be something its temperament is not. Families often find the pointer's combination ideal: you hear about every arrival, guests are welcomed rather than intimidated, children visiting are safe, and nobody has to manage a dog with a hair-trigger around the people you invite in.
Also consider the escape angle. A dog that charges the door barking when the bell rings can slip past visitors, and a fit pointer clears a garden quickly once out. Teach a solid wait at the door, keep a lead by the entrance, and make sure fencing is secure before relying on the dog's homebody instincts.
A backup if your watchdog bolts
Door-dashing is the one security gap a keen pointer can create for itself. If yours bolts while the doorbell chaos is at its peak, turn to KinsLe for another route home: the Lost Pet Alert System sits in his profile at no charge, a map display shows the alert, and someone who spots him can reach you by direct message.