Capability Discovery
Definition
The process by which one agent or system determines what another agent or tool can do at runtime. Capability discovery enables dynamic, composable agent systems where agents aren't hardcoded to specific tools — they discover available capabilities and select the appropriate ones for each task. Discovery mechanisms include: Agent Cards (A2A), tool listings (MCP), OpenAPI specs, and registry queries. Effective capability discovery requires: standardized capability descriptions, semantic matching (understanding what a tool does, not just its name), and trust metadata (is this tool reliable?).
Builder Context
Capability discovery is the foundation of truly flexible agent systems. Instead of hardcoding your agent's available tools, implement a tool router that discovers capabilities at runtime based on the task. Start simple: maintain a tool registry with semantic descriptions, use embedding similarity to match tasks to tools. This approach scales better than adding tools manually to every prompt. The trade-off: dynamic discovery adds latency (one lookup per task) and complexity (what if the best tool is unavailable?).