Premade assistant agent library — 340 agents with pagination

When you create a new AI assistant, the "Choose a Starter Agent" library now includes 340 pre-built agents across 15 categories, so you can start from a template that's much closer to what you actually need. The library adds a new Paid Social Optimization category, and Paid Search has been renamed to Paid Search Optimization. To make the larger selection easy to navigate, the picker now supports search, category filtering, and pagination (50 agents per page, with a "Show All" option).