For all the technology companies large and small talking of smart watches as a mass-market inevitability, those that have launched are muddled and disappointing (see “So Far, Smart Watches Are Pretty Dumb”). But a hands-on demonstration with a new smart watch called the Toq has convinced me that this genre of gadget may yet succeed.

The Toq, made by Qualcomm, doesn’t try to do too much with the limited yet prominent real estate it inhabits on a person’s wrist. And the device can last days between charges thanks to the novel Mirasol display technology owned by Qualcomm.

Although the company’s main business is selling processors for mobile devices, Qualcomm will offer the Toq to consumers by the end of the year. The price is expected to be $300.

Much of the Toq’s appeal comes from the fact that its functions boil down to a simple proposition. It provides a way for important notifications to flow from your smartphone to your wrist, where they can be taken in at a glance and quickly dismissed or acted upon using the device’s always-on color touch screen.

The Toq can be paired with any Android smartphone by installing a companion app. You can then choose which of the apps on your phone can send notifications to your wrist. You can act on some of those notifications when they reach the Toq. For example, you can scroll through a text message on the device’s screen and reply to it in two taps, by selecting from a menu of canned or custom responses.

The Toq doesn’t let you talk into your wrist like Dick Tracy. But it does notify you of an incoming call. With a single tap you can decline a call or accept it, at which point you need to grab your handset to start talking. During a call you can tap on the Toq’s screen to hang up, which could be useful while driving.

As has become standard in the short history of smart watches, the Toq can display several different virtual watch faces. One that Qualcomm says is popular with early testers shows the time and a summary of the next appointment on the user’s calendar. Other watch faces can display stock prices and weather forecasts.

My time with the Toq came courtesy of Rob Chandhok, Qualcomm’s president of interactive platforms, who says that the watch is designed to help people manage the apps and services they already use on their phones, not to be a star in its own right. “That level of at-a-glance, gentle interruption is turning out to be really valuable,” he says. “Most experiences will still be best on phones and tablets, but you will do some smaller things on these devices.”

Chandhok says that Qualcomm will offer APIs that let mobile developers program their apps to be selective about what they push to a Toq. For example, users could manually set an app to buzz their watch with e-mails from only certain people, says Chandhok. Other developers might deploy intelligent filtering technology, “like how Facebook curates your news feed,” he says.

The Toq’s most significant hardware innovation is its screen. Although it doesn’t render colors as richly as a smartphone display, it is very power efficient and works in bright sunlight, thanks to a design that reflects ambient light like the wing of a butterfly (see “Iridescent Displays”). As a result, the Toq can last for an impressive stretch between visits to its wireless charging dock. “It’s not a week, but it is much more than two days,” Chandhok told me.

However, like all smart watches, the Toq is bulky. The device’s main body is slightly larger than its 1.55-inch touch screen (measured on the diagonal), and together with its rubbery strap, it makes the Toq look weighty. On the plus side, it feels balanced on the wrist because its battery is built into the buckle to act as a counterweight to the main body.

Qualcomm and third-party app developers still have a lot of work to do to allow the Toq to deliver Chandhok’s “gentle interruptions.” Yet next to its leading rivals, the Toq looks like the most credible vision of the smart watch yet.

Pebble may be credited with having catalyzed the excitement about smart watches (see “A Smart Watch, Created by the Crowd”), but the company’s product already looks outdated. The watch is operated using fiddly buttons and has a monochrome e-ink display that is slow to refresh. Using a Pebble involves installing special apps to your device, rather than making use of the ones you already use on your smartphone. At the other end of the spectrum, Samsung’s Galaxy Gear is overpowered and overcomplicated. Loaded with an HD camera, a speaker, and a smartphone’s processing power, it requires charging every day and is essentially a shrunken smartphone with a wrist strap.

That’s not to say that the Toq will be wildly popular. Its price is high, and the device doesn’t quite make a compelling case for how smart watches will improve our lives (see “Intel Anthropologist Questions the Smart Watch”). However, the Toq might help the industry solve that problem. Qualcomm is launching it as a kind of experiment, hoping to draw a sizeable crowd of early adopters and inspire other computing companies. Chandhok says some are already in talks with Qualcomm about licensing the Toq’s Mirasol display and other design features.