# Common questions

## What do I use this for today?

Use the [job picker](/docs/jobs). Common paths: write a failing routing eval when the agent guesses, gate prompt/schema PRs with `kit eval ci --suite evals/edd/demo.yaml --threshold-routing 95`, shrink always-on rules with `kit measure-context`, or follow the [feature lifecycle](/docs/lifecycle) when the work is bigger than a prompt tweak. New here? [Start in 10 minutes](/docs/start).

## What is Eval-Driven Development?

EDD is TDD for agents that call tools. You write a failing eval for the tool and arguments you expect, implement the schema and prompt until it passes, then tighten until CI holds.

## How is EDD different from eyeballing prompts?

Each case starts from a fresh context. Tools are mocked, so you measure routing and extraction rather than network luck. Asserts cover JSON schema match plus an optional LLM-as-a-judge. CI can block the merge when routing accuracy drops.

## How do I install kit?

On macOS or Linux, run the installer, then bootstrap the app repo:

`curl -fsSL https://raw.githubusercontent.com/mzworthington/agent-lifecycle-kit/main/install.sh | sh`

Then `kit init . --mcp default --hook`. You need git and Node 22+. If `kit` is not found, add `~/.local/bin` to `PATH`. Full steps: [Getting started](/docs/start).

## How do I run EDD in CI?

Run `kit eval ci --threshold-routing 95 --out out/reports`. The scripted driver works offline with no API key. Live models can be used when `KIT_EVAL_API_KEY` or `OPENAI_API_KEY` is set.

## Do I need an OpenAI key if I use Cursor or GitHub Copilot?

No. Cursor and Copilot are IDE hosts: they load Kit skills and `AGENTS.md`. `kit eval` defaults to the scripted driver and does not call Cursor Chat or Copilot Chat. A provider key is only for optional live-model evals over an OpenAI-compatible HTTP API. Full flow: [EDD guide](/docs/edd).

## What happens after a production miss?

Turn the miss into a JSONL case and add it to the suite. Shadow evals can sample live traffic so the next failure is a test, not a surprise.

## How does kit keep agent context small?

Always-on files (`AGENTS.md`, the project handshake, and thin IDE rules) stay under about 8KB, roughly 2k tokens. Philosophy and SOPs load on demand via kit-knowledge. Run `kit measure-context` for the breakdown; `kit check` fails if that budget is exceeded. Compose one MCP profile per session so unused tool schemas stay out of the prompt. Full write-up: [operator guide](/docs/kit).