If an AI agent can't figure out how your API works, neither can your users

Summary

LLM-powered agents are beginning to look a lot like tireless junior developers. Hand them an API along with the docs and they’ll diligently read the reference, issue a request, parse the error, adjust parameters, and try again and again—on loop—until something works. Frameworks like LangChain and OpenAI function-calling helpers, as well as agents like Cursor, Claude Code, OpenAI Codex, and Codename Goose, make that cycle even easier to wire up and follow.But raw persistence of an agent isn’t always enough. The moment your API’s developer experience falters—an outdated example, a vague 400 payload, an undiscoverable required field—the agent stalls out. That stall is diagnostic. If an algorithm with perfect patience and zero ego can’t figure things out, then a human developer on a deadline is almost certainly hitting the same wall.That symmetry can be a powerful lever. Fix the friction points that trip up agents, and you clear the path for every user, silicon‑ or carbon‑based, to have a great experience using your API.Quick walk-through: how AI agents work with APIsMost agent frameworks follow a ReAct cycle that interleaves reasoning and action, all intended to mirror human problem-solving.Give the agent a task (e.g. “List open PRs”) and a set of tools (e.g. the GitHub /pulls endpoint plus API docs), and it will iterate exactly like a human. It will consult the reference, fire the HTTP call, inspect the JSON or error, tweak its approach, and loop until it lands a 2xx response. To walk through a quick example:Thought: “I need to create a new user via this API. Let me see… The docs show an endpoint POST /users.”Action: Call POST /users with the data it thinks is required (say, it provides a JSON with an email and password).Observation: The API returns 400 Bad Request. (Uh-oh, something’s wrong.)Thought: “The error is just ‘Bad Request’ with no details. I’m not sure what’s missing. Maybe I forgot a field? The docs weren’t clear about required fields. Let me guess and add...