An agile designer should be able to articulate goals and risks and users, frame hypotheses, estimate stories, prioritize work, draft a product roadmap, derive MVPs, run a standup meeting, participate in Design Crit, onboard a new teammate, talk to stakeholders, whiteboard a userflow, win an argument, lose an argument, cut scope, write copy, facilitate a meeting, ask good questions, Get Out Of The Building, take orders, give orders, cooperate, act alone, analyze a new problem, lead a sketching session, let go of an idea (even when it's yours), parse analytics, design experiments, distinguish a bug from a chore, conduct a usability test, tell hard truths in a retro, accept hard truths in a retro, design for delight, write CSS, debug Javascript, commit to Git, pair program, test-drive a feature story, model a domain, craft a brand identity, design a visual system, earn trust, give trust, fight efficiently, die gallantly. Specialization is for insects.
(With apologies to Robert Heinlein)