Agent CreatorSAFE

Model-agnostic agent-skills platform with a harness-free canonical layer, verified adapters, and the ccpi package manager. Explore at tonsofskills.com.

The instruction file, verbatim from the audited commit — this is the text the model reads, and the surface the audit's instruction layer examines. Quoted here so you can judge it without cloning anything.

---
name: agent-creator
description: 'Create production-grade agent .md files aligned with the current Anthropic
  subagent contract.

  Also validates existing agents against the marketplace compliance rules. Use when
  building custom

  subagents, reviewing agent quality, or creating parallel agent architectures for
  orchestrator skills.

  Trigger with "/agent-creator", "create an agent", "build a subagent", or "validate
  my agent".

  Make sure to use this skill whenever creating agents/*.md files for plugins or standalone
  use.

  '
allowed-tools: Read,Write,Edit,Glob,Grep,Bash(python:*),AskUserQuestion,Agent
argument-hint: "<create|validate> [agent path or requirements]"
version: 5.23.0
author: Jeremy Longshore <[email protected]>
license: MIT
tags:
- agent-creation
- validation
- meta-tooling
- subagents
model: inherit
effort: high
compatibility: Designed for Claude Code
---
# Agent Creator

Creates spec-compliant agent .md files following Anthropic's current documented subagent
frontmatter contract. Supports both creation of new agents and validation of existing ones.

## Overview

Agent Creator fills the gap between ad-hoc agent files and production-grade agents that pass
marketplace validation. It distinguishes the 16 fields in Anthropic's public frontmatter table
from runtime-recognized experimental options, then layers the stricter Intent Solutions required
set on top. It prevents
common mistakes (using `allowed-tools` instead of `disallowedTools`, adding invalid fields like
`capabilities` or `expertise_level`), and produces agents with substantive body content that
actually guides Claude's behavior.

Key difference from skill-creator: **agents support both `tools` (allowlist) AND `disallowedTools`
(denylist)**. Skills use `allowed-tools` (allowlist) and, since schema 3.7.0, an optional
kebab-case `disallowed-tools` denylist — a parallel field, not a unification. Agents also support
`effort`, `maxTurns`, `skills`, `memory`, `isolation`, `permissionMode`, `background`, `color`, and
`initialPrompt` — fields that don't exist for skills. Claude Code also recognizes a separately
labeled runtime `experimental` object; do not present it as part of the public 16-field table.
The agent body becomes the **system prompt** that drives the subagent — it does NOT receive the
full Claude Code system prompt.

**Field-naming warning:** Agents use camelCase `disallowedTools:` (canonical sub-agents spec);
skills use kebab-case `disallowed-tools:` (schema 3.7.0+). The validator rejects either mismatch —
never copy-paste between agent and skill frontmatter without renaming.

## Prerequisites

- Claude Code CLI with agent support
- Target directory writable (`agents/` within a plugin or `~/.claude/agents/` for standalone)
- Familiarity with what the agent should specialize in

## Instructions

### Mode Detection

Determine user intent from their prompt:

- **Create mode**: "create an agent", "build a subagent", "new agent" -> Step 1
- **Validate mode**: "validate agent", "check agent", "grade agent" -> Validation Workflow

### Step 1: Understand Requirements

Ask the user with AskUserQuestion:

**Agent Identity:**

- Name (kebab-case, 1-64 chars, e.g., `risk-assessor`, `clause-analyzer`)
- Specialty description (20-1536 chars under the IS contract; keep it concise for the selection UI)

**Execution Context:**

- Plugin agent (`plugins/*/agents/`) or standalone (`~/.claude/agents/`)?
- Will it run as the main `--agent`, or be spawned through the `Agent` tool?
- May it delegate to nested subagents? If yes, include `Agent`; if no, omit or deny it.
- Does it need to preload specific skills? (`skills: [skill-name]`)

**Behavioral Controls:**

- Model override? (`sonnet`, `opus`, `haiku`, `fable`, `inherit`, or a full Claude model ID)
- Reasoning effort? (`low` for simple, `medium` default, `high` for complex analysis)
- Max iterations? (`maxTurns` — how many tool-use loops before stopping)
- Tools to deny? (`disallowedTools` — denylist approach, opposite of skills)

**Plugin Restrictions (if plugin agent):**

- `hooks` — NOT supported in plugin agents (use plugin-level hooks)
- `mcpServers` — NOT supported in plugin agents
- `permissionMode` — standalone only, NOT plugin agents

### Step 2: Plan the Agent

Before writing, determine:

**Agent Role Clarity:**
The agent body must make three things unambiguous:

1. **What it IS responsible for** — its specific domain/methodology
2. **What it is NOT responsible for** — boundaries with other agents
3. **How it communicates results** — output format and structure

**Body Structure Pattern:**
All production agents should follow this body structure:

| Section | Purpose | Required? |
|---------|---------|-----------|
| `# Title` | Agent name as heading | Yes |
| `## Role` | 2-3 sentence domain description with boundaries | Yes |
| `## Inputs` | Parameters the agent receives when spawned | Yes (if spawned by orchestrator) |
| `## Process` | Step-by-step methodology (numbered steps with ### headings) | Yes |
| `## Output Format` | Structured output spec (JSON, markdown, or table) | Yes |
| `## Guidelines` | Do/don't behavioral rules | Yes |
| `## When Activated` | Trigger conditions (when spawned or auto-detected) | Recommended |
| `## Communication Style` | Tone and formatting preferences | Recommended |
| `## Success Criteria` | What good vs poor output looks like | Recommended |
| `## Examples` | Concrete interaction examples | For complex agents |

**Output Structure Decision:**

- If the agent feeds into an orchestrator: use **JSON output** (machine-parseable)
- If the agent is user-facing: use **markdown output** (human-readable)
- If the agent produces both: JSON primary with markdown summary

### Step 3: Write the Agent File

Generate the agent .md using the template from
`${CLAUDE_SKILL_DIR}/../skill-creator/templates/agent-template.md`.
Use `Write` for a new definition and `Edit` for a targeted remediation of an
existing definition; do not r

SAFEgrade B · trust 89/100 Nothing in the source contradicts what it says it does. Grade A is reserved for packages that have also passed the behavioural sandbox.

What the source does

Filesystem

none-observed

Network

none-observed

Shell

none-observed

Dependencies

pinned

Secrets in source

none-found

Findings (0)

No findings outside the package's declared scope.

Gates applied: no_behavioural_pass.