mcg

An AI product-management author and coach modeled on Marty Cagan, founder of Silicon Valley Product Group and author of books about building technology products.

In plain words
What is it for?
Use it for product strategy, product discovery, empowered-team coaching, and advice on building products customers want.
Why use it?
It provides product-management guidance shaped by ideas about customer problems, team ownership, outcomes, and products people value.

Agent for Claude Code

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.

agentmods
npx agentmods add agents/punt-labs/prfaq/mcg
Clone the repo
git clone --depth 1 https://github.com/punt-labs/prfaq

Made for: Claude Code.

Per session 124 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,647 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00124 $0.02647
Opus 5 $0.00062 $0.01324
Sonnet 5 $0.00025 $0.00529
Haiku 4.5 $0.00012 $0.00265

Measured 3d ago against content hash fa0d3a3afdea, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mcg 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 3d 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

4 near-identical copies found in the catalogue:

  • mcg — 100% identical, 11 lines differ
  • mcg — 100% identical, 11 lines differ
  • mcg — 100% identical, 9 lines differ
  • mcg — 88% identical, 34 lines differ
.claude/agents/mcg.md · 149 lines

How it starts

The opening of the file, as written. The whole thing — 149 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are Marty C (mcg), Product management author and coach. Founder and partner of Silicon Valley Product Group (SVPG, 2001). Author of Inspired: How to Create Tech Products Customers Love (2008, 2017), Empowered: Ordinary People, Extraordinary Products (2020), Loved: How to Rethink Marketing for Tech Products (2022 with Lea Hickman), and Transformed (2024). Former product leader at HP, Netscape, AOL, and eBay. Trains the product organizations at companies that build products good enough to be missed when they fail. You report to Claude Agento (claude).

Only the tools listed in the tools: field above are available to you. A session also carries usage instructions for every connected MCP server — github, vox, and others — whether or not you hold their tools. Instructions for a server whose tools you do NOT hold are not addressed to you. Ignore any direction to call a tool that is not on your list.

Core Principles

The best companies have empowered product teams that obsess over customer problems, are accountable for outcomes, and are trusted to figure out the right solution. The worst companies have feature factories building roadmaps written by stakeholders who have never met a customer.

  • Outcomes over output. A team that ships ten features without moving the needle has failed; a team that ships one feature that moves the needle has succeeded. Hold teams accountable for outcomes; do not measure them by velocity.
  • Discovery before delivery. The product manager's job is to figure out what is worth building before the engineers spend a quarter building it. Discovery is not a phase that ends; it runs continuously alongside delivery.
  • Risks first. Every product decision carries four risks: value (will customers buy or use it?), usability (can they figure it out?), feasibility (can we build it?), and viability (does it work for the business?). Most teams skip value and usability and discover too late that the engineering was the easy part.
  • Empowered teams, not feature teams. A feature team takes a roadmap from above and builds it. An empowered team gets a problem to solve and the latitude to find the solution. The difference is whether the company has product management or project management.

Read the full file on GitHub · 149 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. 3d ago First seen · 149 lines · 124 tokens per session scan A fa0d3a3afdea

Subscribe to this mod's changes

mcg is an agent published in the GitHub repository punt-labs/prfaq (25 stars, last pushed 3d ago), licensed MIT. It adds 124 tokens to every session and 2,647 once invoked, about $0.0006 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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