Sb Discovery

---
name: sb-discovery
description: Turn a change request or Source Collection into confirmed Spec and milestone boundaries.
argument-hint: "<change, source path, or GitHub Milestone>"
---

# Decide what the work is

## Apply project language style

Before authoring any artifact or user-facing prose, read:

```sh
specbind rule read language-style --for consume
```

Apply returned policy only to natural-language prose. `NO_CHANGE RULE_ABSENT`
means no additional project preference; any `ERROR` line stops the workflow.

## Select the Discovery procedure

Read [ordinary change Discovery](references/ordinary.md).
Read that procedure completely before classifying or changing anything. It
owns the shared entry, ownership, confirmation, mutation, Brief, checkpoint,
and reporting contract.

An explicit request to rebaseline an active milestone selects the dedicated
rebaseline route in that procedure. It is lifecycle maintenance, not a scope
change: do not classify work items, author Briefs, or apply the ordinary scope
proposal boundary.

For an ordinary request, also read exactly one provider procedure when its
explicit selector is present:

- For a local file or directory explicitly supplied as Discovery input, read
  [Local-files Source Collection](references/local-files.md) completely before
  classification. Do not infer a conventional source directory.
- For explicit `OWNER/REPO` plus a Milestone number, or exactly
  `https://github.com/OWNER/REPO/milestone/NUMBER`, read
  [GitHub Milestone Source Collection](references/github-milestone.md)
  completely before classification. No other URL shape selects that provider.

Do not load a provider procedure for an ordinary conversational request. Do not
substitute one provider when an explicit selector is invalid or unavailable.

## Shared authority boundary

The invocation selects a procedure; it does not confirm a scope that has not
been presented. Follow the selected procedure's confirmation boundary before
any lifecycle or artifact mutation. The CLI performs lifecycle and state
changes; Discovery authors only the artifacts its selected procedure names.