Single functions - a calculator, a search, a SQL runner - with typed inputs.
Tools are the concrete actions a model or agent can take, described so the router knows when to reach for them. Wire them into your own agents or let a plan call them when a request needs a real computation, not a guess.
x402 image tools (USDC/Base): remove_background/upscale $0.02, resize/optimize $0.005; URL in/out
