Gemini 3.8 Flash: Antigravity agy_help Four-Tier Fact-Checking Agent Workflow

One-sentence takeaway

The author uses Gemini 3.8 Flash as a dedicated Q&A agent, agy_help, for the Antigravity CLI: it first checks local structured manuals, then performs read-only environment checks, fetches official documentation when necessary, and refuses to answer when verification is impossible, reducing guesswork around CLI flags, lifecycle event names, and settings.json configuration.

Use cases

• Suitable tasks: Looking up configuration and usage for Antigravity CLI / IDE / Desktop, the Python SDK, Skills, Rules, Hooks, Plugins, and MCP; background documentation retrieval that keeps the main coding session's context clean.

• Unsuitable tasks: General chat, coding tasks unrelated to Antigravity, and tasks that require the agent to modify the workspace or run destructive commands.

• Applicable model version: The post explicitly discusses Gemini 3.8 Flash; it does not provide an API model ID or reasoning-parameter configuration.

• Applicable client, agent, or API: Antigravity CLI (agy), Antigravity IDE / Desktop; agy_help is installed through a plugin.

• Recommended reasoning tier and parameters: The original post does not disclose a reasoning tier, temperature, or other sampling parameters; do not infer API parameters from this case.

Ready-to-use content

Installation and verification (original post text)

agy plugin install https://github.com/andyawd/antigravity-help-agent

After installation, run agy plugin list to check whether the plugin has been registered.

Four-tier fact-checking workflow

agent: agy_help
verification:
  tier_1_local_reference:
    action: aggregate_and_cross_check
    sources:
      - antigravity_guide
      - agy-customizations
  tier_2_local_inspection:
    mode: read_only
    allowed_commands:
      - agy --help
      - agy changelog
      - agy plugin list
      - pip show google-antigravity
    extra: inspect_local_config_files
  tier_3_official_docs:
    when: offline_reference_is_missing_or_stale
    source: https://antigravity.google/docs
  tier_4_grounded_refusal:
    when: feature_cannot_be_verified
    action: refuse_to_guess
safety:
  workspace_mutation: forbidden
  destructive_commands: forbidden

The YAML above is an executable workflow definition organized around the four tiers, command allowlist, and safety guarantees in the original post; the commands and documentation URL remain exactly as listed in the post.

Four invocation methods (copyable text from the original post)

Skills mode, asking directly in the current session:

/agy_help How do I configure project-level sandbox permissions in Antigravity 2.0 Desktop?

Background subagent delegation:

Delegate to the agy_help subagent in the background to look up Antigravity IDE Code Lens configuration and bring back a summary.

Switching to a dedicated session agent:

/agents

Launching directly from the CLI:

agy --agent agy_help

Testing/workflow steps

1. Install the plugin and run agy plugin list to confirm that agy_help is loaded.

2. For Antigravity configuration questions, start with /agy_help <question>; this mode does not switch the current primary agent.

3. When you need to keep the main session's context clean, use background delegation and have agy_help return a summary.

4. The agent first aggregates antigravity_guide and agy-customizations, then runs the allowlisted read-only commands and checks the local configuration.

5. Only access https://antigravity.google/docs when local materials are insufficient; for flags, APIs, or features that still cannot be verified, explicitly state that there is no official record and do not fill in a guess.

6. For conclusions involving versions, configuration hierarchy, or lifecycle, retain command output or official documentation links, and manually review them before applying the conclusion.

Raw evidence and data

• The original post's author explicitly points out that Gemini 3.8 Flash may confidently generate nonexistent CLI flags, incorrect lifecycle hook names, and invalid settings.json schemas while coding; agy_help is the Antigravity CLI plugin the author released for this reason.

• The author says that the agent uses local manuals, local read-only diagnostics, official documentation, and a "refuse when unverifiable" mechanism in sequence, and promises not to run destructive commands or secretly modify the workspace.

• The original post provides an installation command, a CLI launch command, a skills-mode example, and a background subagent delegation example. This makes the "install → query/delegate → multi-layer verification → summary or refusal" workflow reproducible, but it does not disclose an API request body, the complete system prompt, or a quantitative accuracy experiment.

Applicability boundaries

• "zero-hallucination" is the author's name for the design goal, not an independently tested guarantee of zero hallucinations; local material may be wrong, versions may change, and network fetching may fail, so human review is still required.

• This approach depends on Antigravity CLI's plugins, slash commands, /agents, and local documentation structure. It cannot be used directly as a configuration guide for the Gemini API, Google AI Studio, or other IDEs.

• Although the Tier 2 commands are on a read-only allowlist, they may still expose the local machine's version or configuration summary; redact logs before sharing them. Tier 3 requires a network connection, and results may differ when the official documentation changes.

• The original post does not explain Gemini 3.8 Flash's thinking_level, temperature, token limit, or price. Do not apply parameters from the official API documentation to this CLI plugin without checking compatibility.

Source excerpt or observation (compliance short quote only)

The author's core rule is that if a flag, API, or feature cannot be verified in the preceding tiers, "it is strictly forbidden from guessing." This shows that the key to the workflow is not stacking a longer prompt, but putting verifiable evidence and refusal conditions into the agent's routing.