Claude Code Agent Development
anthropics/claude-plugins-official
Explains how to write agents for Claude Code plugins: the markdown file with YAML frontmatter, trigger descriptions, model and color settings, and system prompt design.
Gets an independent critique of recent work and session direction from the adversarial-review subagent.
Install Adversarial Review
$ npx skills add ropensci/ckanr --skill adversarial-review -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install ropensci/ckanr adversarial-review --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/ropensci/ckanr.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/adversarial-review .claude/skills/adversarial-review && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "adversarial-review" agent skill from https://github.com/ropensci/ckanr/tree/main/.agents/skills/adversarial-review into .claude/skills/adversarial-review/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "adversarial-review", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/ropensci/ckanr/tree/main/.agents/skills/adversarial-reviewType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add ropensci/ckanr --skill adversarial-review -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install ropensci/ckanr adversarial-review --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/ropensci/ckanr.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/adversarial-review .agents/skills/adversarial-review && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "adversarial-review" agent skill from https://github.com/ropensci/ckanr/tree/main/.agents/skills/adversarial-review into .agents/skills/adversarial-review/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "adversarial-review", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add ropensci/ckanr --skill adversarial-review -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install ropensci/ckanr adversarial-review --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/ropensci/ckanr.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/adversarial-review .cursor/skills/adversarial-review && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "adversarial-review" agent skill from https://github.com/ropensci/ckanr/tree/main/.agents/skills/adversarial-review into .cursor/skills/adversarial-review/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "adversarial-review", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/ropensci/ckanr.git --path .agents/skills/adversarial-review--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add ropensci/ckanr --skill adversarial-review -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install ropensci/ckanr adversarial-review --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/ropensci/ckanr.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/adversarial-review .gemini/skills/adversarial-review && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "adversarial-review" agent skill from https://github.com/ropensci/ckanr/tree/main/.agents/skills/adversarial-review into .gemini/skills/adversarial-review/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "adversarial-review", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install ropensci/ckanr adversarial-reviewInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add ropensci/ckanr --skill adversarial-review -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/ropensci/ckanr.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/adversarial-review .github/skills/adversarial-review && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "adversarial-review" agent skill from https://github.com/ropensci/ckanr/tree/main/.agents/skills/adversarial-review into .github/skills/adversarial-review/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "adversarial-review", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add ropensci/ckanr --skill adversarial-review -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install ropensci/ckanr adversarial-review --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/ropensci/ckanr.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/adversarial-review .opencode/skills/adversarial-review && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "adversarial-review" agent skill from https://github.com/ropensci/ckanr/tree/main/.agents/skills/adversarial-review into .opencode/skills/adversarial-review/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "adversarial-review", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
adversarial-review- GitHub stars
- 104
- Token cost
- ~522 tokens
- SKILL.md length
- 197 words
- Files
- 1
- Skills in repo
- 2
- Repo updated
- First seen
- Licence
- Custom licence
At a glance
Gets an independent critique of recent work and session direction from the adversarial-review subagent.
- A second opinion
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
- Hardest critique
- Highest-value improvements
What it does
Adversarial Review is an agent skill from ropensci/ckanr. Gets an independent critique of recent work and session direction from the adversarial-review subagent. Use for a second opinion, hardest critique, or highest-value improvements.
Its SKILL.md is about 520 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Agent Workflows, covering Subagents. The repository describes itself as: R client for the CKAN API.
When your agent uses it
- A second opinion
- Hardest critique
- Highest-value improvements
Example prompts
- “/adversarial-review”
What it can do on your machine
Read from SKILL.md and the folder at commit 8941780. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Adversarial Review loads about 522 tokens when it runs. Until then it costs about 49 tokens; SKILL.md has 197 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
Its licence (Custom licence) doesn't allow us to republish the file, so here is its outline and opening line. It has 197 words (~522 tokens).
“Launch exactly one adversarial-review subagent with:”
- name
- adversarial-review
- metadata.opencode/autoinvoke
- true
Files
Just SKILL.md in .agents/skills/adversarial-review of ropensci/ckanr.
Open the folder on GitHubat commit 8941780
Compare with similar skills
Adversarial Review next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Adversarial Review this skillropensci/ckanr | 104 | — | ~522 | Automated safety check: Pass | Custom licence | |
| Claude Code Agent Developmentanthropics/claude-plugins-official | 38k | 7 repos | ~2.8k | Automated safety check: Pass | Apache-2.0 | |
| Subagent Driven DevelopmentAsvarox/allkaraoke | 261 | 38 repos | ~1.2k | Automated safety check: Pass | None | |
| Dispatching Parallel Agentsultralisp/ultralisp | 258 | 41 repos | ~1.5k | Automated safety check: Pass | None | |
| Reflect on Session Learningscursor/plugins | 11k | 5 repos | ~1.2k | Automated safety check: Pass | None | |
| Paseo Advisor Second Opiniongetpaseo/paseo | 20k | 1 repos | ~756 | Automated safety check: Pass | Custom licence |
Similar skills
- Official
Subagent Driven Development
Asvarox/allkaraoke
A skill your agent uses when executing implementation plans with independent tasks in the current session
Dispatching Parallel Agents
ultralisp/ultralisp
A skill your agent uses when facing 2+ independent tasks that can be worked on without shared state or sequential dependencies
- Official
Reflect on Session Learnings
cursor/plugins
Starts three parallel reviewer subagents over the current conversation transcript, then turns their findings into concrete edits to existing skills.
Paseo Advisor Second Opinion
getpaseo/paseo
Launches one separate agent through Paseo to give a second opinion on the current task, with a self-contained briefing and no permission to edit files.
Task Observer
rebelytics/one-skill-to-rule-them-all
Monitors task execution for skill improvement opportunities.
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Questions about Adversarial Review
What does Adversarial Review do?
Gets an independent critique of recent work and session direction from the adversarial-review subagent. Adversarial Review is an agent skill from ropensci/ckanr. Gets an independent critique of recent work and session direction from the adversarial-review subagent.
When should I use Adversarial Review?
Adversarial Review fits situations like: A second opinion; hardest critique; highest-value improvements.
How do I install Adversarial Review in Claude Code?
Run `npx skills add ropensci/ckanr --skill adversarial-review -a claude-code`. Or copy the skill folder (.agents/skills/adversarial-review in ropensci/ckanr) into .claude/skills/adversarial-review in your project. Claude Code loads it when a task matches its description.
How do I install Adversarial Review in Codex?
Run `npx skills add ropensci/ckanr --skill adversarial-review -a codex`. Or copy the skill folder (.agents/skills/adversarial-review in ropensci/ckanr) into .agents/skills/adversarial-review in your project. Codex loads it when a task matches its description.
Can I use Adversarial Review in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add ropensci/ckanr --skill adversarial-review -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/adversarial-review, .gemini/skills/adversarial-review, .github/skills/adversarial-review and .opencode/skills/adversarial-review in your project.
What does Adversarial Review need to run?
SKILL.md names no scripts, command-line tools or credentials: Adversarial Review is instructions for the agent only.
Does Adversarial Review access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Adversarial Review safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Adversarial Review use?
Adversarial Review has a licence file (the repository's licence) that doesn't match a standard licence. Read it on GitHub before reusing the skill.
How many tokens does Adversarial Review use?
About 522 tokens (SKILL.md is roughly 2.1k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Adversarial Review?
Skills that share tags, products or a category with Adversarial Review: Claude Code Agent Development (anthropics/claude-plugins-official, 38k stars), Subagent Driven Development (Asvarox/allkaraoke, 261 stars), Dispatching Parallel Agents (ultralisp/ultralisp, 258 stars) and Reflect on Session Learnings (cursor/plugins, 11k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Adversarial Review?
ropensci (a GitHub organization) maintains it in ropensci/ckanr, which has 104 GitHub stars. The repository holds 2 skills in this directory. The repository was last updated on October 10, 2026.
Source: ropensci/ckanr on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.