Heat 1 tablespoon olive oil in a large nonstick skillet over medium-high heat.
Add the onion and cook, stirring occasionally, until slightly softened, about 5 minutes.
Stir in the bell peppers and 1/2 teaspoon fajita seasoning. Cook for 3 minutes, stirring occasionally, until the veggies begin to soften.
Add 1/4 cup water to the skillet and cook until the vegetables are tender, about 5 more minutes. Remove from heat.
In a bowl, whisk half the lime juice with 1 1/2 tablespoons olive oil and the agave. Mix in half the cilantro, then toss with the cooked onion and peppers. Set aside.
Wipe the skillet clean, then heat it over high heat. Toss the shrimp with the remaining 1/2 tablespoon olive oil and 1/4 teaspoon fajita seasoning in a separate bowl.
Add the shrimp to the skillet and cook until pink, about 2-3 minutes per side. Remove from heat and toss with the remaining lime juice and cilantro. Season with salt and pepper.
Warm the tortillas according to package instructions.
In serving bowls, layer shredded lettuce, the onion and pepper mixture, shrimp, and pico de gallo. Serve with tortillas and lime wedges on the side. Enjoy!