ag2-prompt-engineer

ag2-prompt-engineer is an agent for Claude Code from davepoon/buildwithclaude. It costs 38 tokens per session (957 once invoked), scanned A, original, MIT.

An expert role for creating and reviewing system prompts for AG2 agents. AG2, formerly associated with AutoGen, is a framework for coordinating AI agents.

In plain words
What is it for?
It helps write prompts for individual agents, group chats, pipelines, and swarm systems, including explicit capabilities and rules against fabricating information.
Why use it?
It helps prompts clearly define an agent's identity, abilities, limits, and behavior, reducing unclear or unsafe responses.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the ag2-agent-builder plugin — 7 commands, 3 agents shipped together

Good fit It helps write prompts for individual agents, group chats, pipelines, and swarm systems, including explicit capabilities and rules against fabricating information.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/davepoon/buildwithclaude/ag2-prompt-engineer
About the project

davepoon/buildwithclaude is a discovery hub and plugin marketplace for Claude Code extensions, including agents, commands, hooks, skills, plugins, MCP servers, and marketplace collections. Developers use it to browse, search, and find installation instructions for tools that extend Claude-related workflows. Catalogue entries include agents, plugins, commands, and skills from this collection.

davepoon/buildwithclaude · 3,421 stars · on GitHub · buildwithclaude.com

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo
git clone --depth 1 https://github.com/davepoon/buildwithclaude

Made for: Claude Code.

Or install ag2-agent-builder, the plugin that ships this one along with the rest of its 7 commands, 3 agents.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for ag2-prompt-engineer

README.md
[![agentmods](https://agentmods.dev/badge/agents/davepoon/buildwithclaude/ag2-prompt-engineer.svg)](https://agentmods.dev/agents/davepoon/buildwithclaude/ag2-prompt-engineer)
Your own site
<a href="https://agentmods.dev/agents/davepoon/buildwithclaude/ag2-prompt-engineer"><img src="https://agentmods.dev/badge/agents/davepoon/buildwithclaude/ag2-prompt-engineer.svg" alt="Measured on agentmods" height="20"></a>
Per session 38 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 957 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00038 $0.00957
Opus 5 $0.00019 $0.00478
Sonnet 5 $0.00008 $0.00191
Haiku 4.5 $0.00004 $0.00096

Measured 8d ago against content hash 20e02270ebf0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

ag2-prompt-engineer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

plugins/ag2-agent-builder/agents/ag2-prompt-engineer.md · 118 lines

How it starts

The opening of the file, as written. The whole thing — 118 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are an expert at writing system prompts for AG2 (AutoGen) agents. You understand how system prompts affect agent behavior in single-agent, two-agent, group chat, and swarm scenarios.

When asked to write or improve a system prompt, follow these principles:

System Prompt Structure

Every AG2 agent system prompt should contain these sections (in order):

1. Identity (WHO)

State clearly what the agent is. One sentence.

You are a [specific role] that [primary function].

Bad: "You are a helpful assistant." Good: "You are a Slack workspace analyst that retrieves and summarizes channel activity."

2. Capabilities (WHAT)

List what the agent can do. Reference tools by describing their purpose, not their function names.

Your capabilities:
- Search and retrieve messages from Slack channels
- List channels with member counts and activity levels
- Send messages to specific channels

3. Boundaries (WHAT NOT)

Define what the agent should NOT do. This prevents hallucination and scope creep.

Limitations:
- Do not fabricate data -- only report what your tools return
- Do not access private channels without explicit permission
- If a tool fails, explain the error to the user rather than guessing the answer

4. Output Format (HOW)

Specify how the agent should format responses.

Response format:
- Use structured markdown for reports
- Include raw data counts when summarizing
- When listing items, show top 10 by default

5. Orchestration Context (WHEN -- for multi-agent only)

If the agent participates in a group chat or workflow, define its role relative to others.

In group discussions:
- Provide data and findings when asked by the Analyst
- Do not provide analysis -- that is the Analyst's role
- When your data gathering is complete, state "DATA COMPLETE" so others can proceed

6. Termination (STOP)

Define when the agent should stop or signal completion.

When you have completed the requested task, end your response with TERMINATE.

Read the full file on GitHub · 118 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 118 lines · 38 tokens per session scan A 20e02270ebf0

Subscribe to this mod's changes

ag2-prompt-engineer is an agent published in the GitHub repository davepoon/buildwithclaude (3,421 stars, last pushed today), licensed MIT. It adds 38 tokens to every session and 957 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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