MCP Server Builder
anthropics/skills
Guides the design and implementation of Model Context Protocol servers in TypeScript or Python, from tool naming and error messages to evaluation.
A skill your agent uses when the agent needs to check whether an ALFWorld task objective has been met after completing a sub-action (e.g., placing an object).
Install Alfworld Task Verifier
$ npx skills add zjunlp/SkillNet --skill alfworld-task-verifier -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install zjunlp/SkillNet alfworld-task-verifier --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/zjunlp/SkillNet.git skills-src && mkdir -p .claude/skills && cp -r skills-src/experiments/src/skills/alfworld/alfworld-task-verifier .claude/skills/alfworld-task-verifier && 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 "alfworld-task-verifier" agent skill from https://github.com/zjunlp/SkillNet/tree/main/experiments/src/skills/alfworld/alfworld-task-verifier into .claude/skills/alfworld-task-verifier/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "alfworld-task-verifier", 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/zjunlp/SkillNet/tree/main/experiments/src/skills/alfworld/alfworld-task-verifierType 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 zjunlp/SkillNet --skill alfworld-task-verifier -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install zjunlp/SkillNet alfworld-task-verifier --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/zjunlp/SkillNet.git skills-src && mkdir -p .agents/skills && cp -r skills-src/experiments/src/skills/alfworld/alfworld-task-verifier .agents/skills/alfworld-task-verifier && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "alfworld-task-verifier" agent skill from https://github.com/zjunlp/SkillNet/tree/main/experiments/src/skills/alfworld/alfworld-task-verifier into .agents/skills/alfworld-task-verifier/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "alfworld-task-verifier", 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 zjunlp/SkillNet --skill alfworld-task-verifier -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install zjunlp/SkillNet alfworld-task-verifier --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/zjunlp/SkillNet.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/experiments/src/skills/alfworld/alfworld-task-verifier .cursor/skills/alfworld-task-verifier && 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 "alfworld-task-verifier" agent skill from https://github.com/zjunlp/SkillNet/tree/main/experiments/src/skills/alfworld/alfworld-task-verifier into .cursor/skills/alfworld-task-verifier/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "alfworld-task-verifier", 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/zjunlp/SkillNet.git --path experiments/src/skills/alfworld/alfworld-task-verifier--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 zjunlp/SkillNet --skill alfworld-task-verifier -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install zjunlp/SkillNet alfworld-task-verifier --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/zjunlp/SkillNet.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/experiments/src/skills/alfworld/alfworld-task-verifier .gemini/skills/alfworld-task-verifier && 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 "alfworld-task-verifier" agent skill from https://github.com/zjunlp/SkillNet/tree/main/experiments/src/skills/alfworld/alfworld-task-verifier into .gemini/skills/alfworld-task-verifier/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "alfworld-task-verifier", 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 zjunlp/SkillNet alfworld-task-verifierInstalls 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 zjunlp/SkillNet --skill alfworld-task-verifier -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/zjunlp/SkillNet.git skills-src && mkdir -p .github/skills && cp -r skills-src/experiments/src/skills/alfworld/alfworld-task-verifier .github/skills/alfworld-task-verifier && 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 "alfworld-task-verifier" agent skill from https://github.com/zjunlp/SkillNet/tree/main/experiments/src/skills/alfworld/alfworld-task-verifier into .github/skills/alfworld-task-verifier/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "alfworld-task-verifier", 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 zjunlp/SkillNet --skill alfworld-task-verifier -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install zjunlp/SkillNet alfworld-task-verifier --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/zjunlp/SkillNet.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/experiments/src/skills/alfworld/alfworld-task-verifier .opencode/skills/alfworld-task-verifier && 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 "alfworld-task-verifier" agent skill from https://github.com/zjunlp/SkillNet/tree/main/experiments/src/skills/alfworld/alfworld-task-verifier into .opencode/skills/alfworld-task-verifier/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "alfworld-task-verifier", 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
alfworld-task-verifier- GitHub stars
- 1.4k
- Token cost
- ~754 tokens
- SKILL.md length
- 289 words
- Files
- 3 (incl. references)
- Skills in repo
- 122
- Repo updated
- First seen
- Licence
- MIT
At a glance
A skill your agent uses when the agent needs to check whether an ALFWorld task objective has been met after completing a sub-action (e.g., placing an object).
- Works in 4 steps: Parse the Task Goal → Analyze the Observation → Make a Verification Decision → …
- The agent needs to check whether an ALFWorld task objective has been met after completing a sub-action (e.g.
- SKILL.md covers When to Use, Core Workflow, Example and Error Handling
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Alfworld Task Verifier is an agent skill from zjunlp/SkillNet. Use when the agent needs to check whether an ALFWorld task objective has been met after completing a sub-action (e.g., placing an object). This skill parses the task goal, evaluates the latest environment observation, and outputs a verification decision — task complete, task incomplete, or action ineffective — to guide the next step.
Its SKILL.md is about 750 tokens, which your agent loads only when the skill is triggered. The skill folder holds 3 other files, including reference files (for example `references/task_grammar.md` and `references/verification_examples.md`).
It sits in Agent Workflows. The repository describes itself as: Create, Evaluate, and Connect AI Skills. The licence is MIT.
When your agent uses it
- The agent needs to check whether an ALFWorld task objective has been met after completing a sub-action (e.g.
- Placing an object)
Example prompts
- “/alfworld-task-verifier”
Workflow steps
4 steps, taken from the step headings in SKILL.md.
What it can do on your machine
Read from SKILL.md and the folder at commit 3fcebf8. 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
Alfworld Task Verifier loads about 754 tokens when it runs, and up to ~1.9k if it reads all its reference files. Until then it costs about 90 tokens; SKILL.md has 289 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
The full file from zjunlp/SkillNet at commit 3fcebf8, republished under its MIT licence (© zjunlp). 289 words, ~754 tokens.
Download SKILL.mdSave it as
.claude/skills/alfworld-task-verifier/SKILL.md (or your agent's skills folder). This skill also uses 2 other files; get the full folder from GitHub.- name
- alfworld-task-verifier
- description
- Use when the agent needs to check whether an ALFWorld task objective has been met after completing a sub-action (e.g., placing an object). This skill parses the task goal, evaluates the latest environment observation, and outputs a verification decision — task complete, task incomplete, or action ineffective — to guide the next step.
Skill: Task Verifier for ALFWorld
When to Use
Trigger this skill when:
- The agent has just completed a key sub-action (e.g.,
put {obj} in/on {recep}) - The agent needs to determine whether the overall task goal is satisfied
- The agent must decide whether to continue searching or conclude the task
Core Workflow
1. Parse the Task Goal
Extract from the original task description:
- Target object(s): What needs to be found/placed (including quantity)
- Target receptacle: Where objects must end up
- Required transformations: Any cleaning, heating, or cooling steps
2. Analyze the Observation
Evaluate the most recent Observation: text from the environment:
- Look for evidence that required objects are present in the target receptacle
- Count how many target objects have been successfully placed
- Note: Other items in the receptacle do not invalidate success
3. Make a Verification Decision
| Condition | Decision | Output |
|---|---|---|
| All required objects confirmed in target receptacle | Complete | Verification: Task complete. No further action needed. |
| Some but not all objects placed | Incomplete | Verification: Task incomplete. Continue searching for {missing object(s)}. |
| Observation says "Nothing happened" | Ineffective | Verification: Last action was ineffective. Re-assess and try a different approach. |
| Object placed in wrong receptacle | Incorrect | Verification: Object placed in wrong location. Retrieve and redirect to {correct receptacle}. |
4. Output Format
Output only the verification decision. Do not output the next action. This skill informs the planning for the next step, not the execution.
Example
Task: "Find two pen and put them in garbagecan."
Action: put pen 3 in/on garbagecan 1
Observation: You put the pen 3 in/on the garbagecan 1.
> Verification: Task incomplete. Continue searching for pen (1 of 2 placed).
Action: put pen 1 in/on garbagecan 1
Observation: You put the pen 1 in/on the garbagecan 1.
> Verification: Task complete. No further action needed.Example — Failed action:
Action: put pen 3 in/on garbagecan 1
Observation: Nothing happened.
> Verification: Last action was ineffective. Re-assess and try a different approach.Error Handling
- Ambiguous observation: If the observation does not clearly confirm or deny placement, navigate to the target receptacle and re-examine it to get an updated state.
- Quantity tracking: For multi-object tasks, maintain a running count. Re-examine the target receptacle if the count is uncertain.
© zjunlp, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 2 other files (references) in experiments/src/skills/alfworld/alfworld-task-verifier of zjunlp/SkillNet.
- SKILL.md
- references/task_grammar.md
- references/verification_examples.md
Open the folder on GitHubat commit 3fcebf8
Compare with similar skills
Alfworld Task Verifier 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 |
|---|---|---|---|---|---|---|
| Alfworld Task Verifier this skillzjunlp/SkillNet | 1.4k | — | ~754 | Automated safety check: Pass | MIT | |
| MCP Server Builderanthropics/skills | 180k | 64 repos | ~2.3k | Automated safety check: Pass | Apache-2.0 | |
| Hook Development for Claude Code Pluginsanthropics/claude-plugins-official | 38k | 11 repos | ~4.1k | Automated safety check: Notes | Apache-2.0 | |
| Using Superpowersfarm-fe/farm | 5.6k | 35 repos | ~1.4k | Automated safety check: Pass | MIT | |
| Executing Plans Inlineobra/superpowers | 296k | 2 repos | ~5.1k | Automated safety check: Pass | MIT | |
| Claude Code Agent Developmentanthropics/claude-plugins-official | 38k | 8 repos | ~2.8k | Automated safety check: Pass | Apache-2.0 |
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Performs an initial scan of the ALFWorld environment to identify all visible objects and receptacles.
Alfworld Receptacle Searcher
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Related
Categories
Questions about Alfworld Task Verifier
What does Alfworld Task Verifier do?
A skill your agent uses when the agent needs to check whether an ALFWorld task objective has been met after completing a sub-action (e.g., placing an object). Alfworld Task Verifier is an agent skill from zjunlp/SkillNet., placing an object).
When should I use Alfworld Task Verifier?
Alfworld Task Verifier fits situations like: the agent needs to check whether an ALFWorld task objective has been met after completing a sub-action (e.g; placing an object).
How do I install Alfworld Task Verifier in Claude Code?
Run `npx skills add zjunlp/SkillNet --skill alfworld-task-verifier -a claude-code`. Or copy the skill folder (experiments/src/skills/alfworld/alfworld-task-verifier in zjunlp/SkillNet) into .claude/skills/alfworld-task-verifier in your project. Claude Code loads it when a task matches its description.
How do I install Alfworld Task Verifier in Codex?
Run `npx skills add zjunlp/SkillNet --skill alfworld-task-verifier -a codex`. Or copy the skill folder (experiments/src/skills/alfworld/alfworld-task-verifier in zjunlp/SkillNet) into .agents/skills/alfworld-task-verifier in your project. Codex loads it when a task matches its description.
Can I use Alfworld Task Verifier 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 zjunlp/SkillNet --skill alfworld-task-verifier -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/alfworld-task-verifier, .gemini/skills/alfworld-task-verifier, .github/skills/alfworld-task-verifier and .opencode/skills/alfworld-task-verifier in your project.
What does Alfworld Task Verifier need to run?
SKILL.md names no scripts, command-line tools or credentials: Alfworld Task Verifier is instructions for the agent only.
Does Alfworld Task Verifier 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 Alfworld Task Verifier 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 Alfworld Task Verifier use?
Alfworld Task Verifier is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Alfworld Task Verifier use?
About 754 tokens (SKILL.md is roughly 3k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 1.1k tokens, read only when the agent opens those files.
What are the alternatives to Alfworld Task Verifier?
Skills that share tags, products or a category with Alfworld Task Verifier: MCP Server Builder (anthropics/skills, 180k stars), Hook Development for Claude Code Plugins (anthropics/claude-plugins-official, 38k stars), Using Superpowers (farm-fe/farm, 5.6k stars) and Executing Plans Inline (obra/superpowers, 296k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Alfworld Task Verifier?
zjunlp (a GitHub organization) maintains it in zjunlp/SkillNet, which has 1,393 GitHub stars. The repository holds 122 skills in this directory. The repository was last updated on October 7, 2026.
Source: zjunlp/SkillNet on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.