How to use the Phase Gate Check agent skill (gate-check)

What is an agent skill and what does gate-check make the agent do?

An agent skill is a folder of instructions and optional helper scripts that an AI agent loads when a request matches the skill's purpose. gate-check is designed for game projects built on the Claude Code Game Studios template.

When you ask whether the project can advance, the agent looks for the required documents, tests and other artifacts defined for that transition. It then returns a verdict such as PASS, CONCERNS, NOT ASSESSED or FAIL, with blockers listed. If the gate passes, it can update the project's stage in project.yaml and production/stage.txt.

• Checks the transition you name, for example Pre-Production to Production.
• Lists blockers and the required artifacts that are still missing.
• Asks for confirmation before running and is meant as a deliberate human checkpoint.

Install the gate-check skill

Download the gate-check ZIP from this page and unzip it. Place the gate-check folder in one of these locations: ~/.claude/skills/ for all your projects, or .claude/skills/ inside a specific project.

If you use the Claude apps instead, open Settings, go to Capabilities, then Skills, and upload the ZIP there.

• Personal install: ~/.claude/skills/gate-check
• Project install: .claude/skills/gate-check inside your game project
• Claude apps: Settings → Capabilities → Skills → upload the ZIP

Check what you need before running it

gate-check needs a Bash shell so it can run its helper scripts, and it needs the project files from the Claude Code Game Studios template. The skill's frontmatter sets its model to opus, so the Claude Code runtime must be set to that model.

The checklists assume the template's files exist, including project.yaml, the production/ folder, and the hooks and scripts under .claude. Without them the checks cannot be meaningfully completed.

• Bash shell available for helper scripts such as yaml-helper.sh, artifact-check.sh, gdd-structure-check.sh, adr-dep-graph.sh and set-stage.sh
• Template project files: project.yaml, production/, and .claude hooks and scripts
• Claude Code runtime with model set to opus

Trigger the skill with natural requests

You can name a target phase explicitly or let the skill detect the current stage. Without an argument, the agent first proposes the current stage and the next transition, and asks you to confirm before it runs. Its argument hint lists the target phases as systems-design, technical-setup, pre-production, production, polish and release, with an optional --review full, lean or solo setting.

Natural requests such as asking whether the project can move to production should also reach the skill, because its description includes that question.

• "Can we move to production?"
• "Run the phase gate for pre-production."
• "What is still blocking the move to polish?"
• Slash form with a phase: /gate-check production
• Slash form with a mode: /gate-check --review lean

Read the verdict and act on it

The verdict tells you how ready the project is. NOT ASSESSED means the gate could not check part of its scope, and it ranks above PASS, so a gate that could not check everything has not established readiness. CONCERNS means the listed risks can be accepted explicitly by you, after which the stage can be advanced.

A PASS, or a CONCERNS verdict where you accept the listed risks, is what triggers the stage update in project.yaml and production/stage.txt.

• PASS: all required items are present and the gate is satisfied.
• CONCERNS: risks are listed; you decide whether to accept them.
• NOT ASSESSED: part of the gate could not be checked; treat as not yet ready.
• FAIL: blockers must be resolved before advancing.

Safety notes: scripts and network

gate-check runs helper scripts through Bash, so review the scripts under .claude before running the skill on a project you care about. According to the skill's own metadata, it does not use the network.

The skill writes to project files when a gate passes, so keep a version-control commit before running it so you can see and revert the stage change.

• It runs scripts: yes. Read them first.
• It uses network: no, according to its metadata.
• It can write the new stage to project.yaml and production/stage.txt on PASS.

Tips for a useful gate review

Run the gate as a deliberate checkpoint rather than a quick question, and keep the artifacts it names up to date first. Use the diagnostic skill /project-stage-detect when you only want to know which stage you are in, since that is the tool designed for it.

• Run /project-stage-detect first if you only want to know your stage.
• Use /gate-check --review lean or solo to change how many reviews run, if your team is small.
• Expect the skill to ask for confirmation before it runs; it will not approve automatically.