# Adversarial review
The `adversarial-review` skill launches one independent, read-only
`adversarial-review` subagent to challenge recent work or a proposed direction.
The subagent inspects the repository itself; the host only supplies the repository
path and relevant session context.
## Quick start
Ask your agent:
```text
Use the adversarial-review skill to review our changes and proposed next steps.
Use the adversarial-review skill on the diff against main.
Use the adversarial-review skill to challenge this plan before implementation.
```
The result is a proceed/course-correct/rethink verdict, up to five actionable
improvements, material evidence gaps, and the best next action. The review is
advice: changes are made only when you request them.
## How it works
The host launches exactly one named subagent in the foreground unless you ask for
background execution. It does not choose another CLI or model, persist reviewer
preferences, or prepare a broad diff. The read-only subagent inspects the relevant
repository state and returns its review.
The host passes only context the subagent cannot recover from the checkout:
```text
Full Repository Path: <absolute path>
Review Scope: <requested files/diff/commits/plan, or infer from current work>
User Goal: <requested outcome>
Session Direction: <recent decisions and proposed next steps>
Constraints: <material user or project constraints>
Checks Run: <commands and actual results>
Known Failures or Uncertainties: <material gaps>
Custom Instructions: <specific review focus from the user>
```
The first four lines are always included; the others are included only when they
have useful values.
Use it at meaningful checkpoints: before committing to an uncertain design, after
substantial changes and focused checks, or when deciding which remaining problem
deserves attention. State the decision or scope you want challenged. Confirmed
defects, hypotheses, and risks in proposed work should remain distinct.
For deterministic, enumerated repository coverage and a `REVIEW.md` report, use
the [oy-review workflow](workflows.md#review-scope-and-focus) instead.
## Install
The host must support Agent Skills and provide a named `adversarial-review`
subagent with read-only repository tools. The skill does not install or emulate
that subagent. If it is unavailable, configure it through your agent host before
using this skill.
### With oy
`oy setup` installs the skill globally, or use `--workspace` for the current
repository only:
```bash
oy setup # ~/.agents/skills/; use --workspace for .agents/skills/
oy doctor --check
```
Then ask your agent to `run the oy-setup skill` to verify discovery and catch stale
host-specific copies. See [Getting started](getting-started.md) if you need oy.
### Install just this skill
The skill is one Markdown file and does not require the oy binary. Save the
[raw SKILL.md](https://raw.githubusercontent.com/adonm/oy-cli/main/assets/skills/adversarial-review/SKILL.md),
or copy the [full skill below](#full-skill), including its YAML frontmatter:
| Global | `~/.agents/skills/adversarial-review/SKILL.md` |
| Repository | `.agents/skills/adversarial-review/SKILL.md` |
Use your host's supported skill directory when it differs; see
[Compatibility](compatibility.md#agent-skills-hosts). Preserve existing custom
definitions. The `Generated by oy setup` marker makes a copy oy-managed during
later setup; remove the marker before maintaining a customized copy.
Reload skill discovery or start a new session, then ask the host to identify the
loaded definition and its path. `oy doctor --check` validates the full oy bundle;
for a single-file install, verify discovery in the host itself.
## Reference from contributing instructions
Copy this into a repository's `CONTRIBUTING.md` or agent instructions:
```markdown
For substantial changes or uncertain design decisions, use the
[adversarial-review skill](https://oy.adonm.dev/adversarial-review.html) to
challenge the work and proposed next steps. Provide the goal, constraints, and
actual check results; let the read-only subagent inspect the repository itself.
Treat the result as advice and validate findings before acting on them.
```
## Full skill
The published page includes the canonical file directly at build time.
[View source](https://github.com/adonm/oy-cli/blob/main/assets/skills/adversarial-review/SKILL.md)
or [download SKILL.md](https://raw.githubusercontent.com/adonm/oy-cli/main/assets/skills/adversarial-review/SKILL.md).
````markdown
{{#include ../assets/skills/adversarial-review/SKILL.md}}
````