design-ousterhout

design-ousterhout is an agent for coding agents from nikolasrieble/opencode-config. It costs 13 tokens per session (272 once invoked), scanned A, original, Apache-2.0.

A code-review guide based on John Ousterhout's book *A Philosophy of Software Design*. It focuses on finding unnecessary complexity, unclear module boundaries, repeated layers, and comments or fixes that make code harder to understand.

In plain words
What is it for?
Use it when reviewing a change for overly complicated modules, leaked implementation details, pass-through code, excessive error handling, tactical fixes, or comments that explain what instead of why.
Why use it?
It gives reviewers a structured way to identify design problems rather than focusing only on whether code works. Each finding includes the relevant design principle, affected code, and a concrete simplification.

Agent

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/nikolasrieble/opencode-config/design-ousterhout
Clone the repo
git clone --depth 1 https://github.com/nikolasrieble/opencode-config

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 design-ousterhout

README.md
[![agentmods](https://agentmods.dev/badge/agents/nikolasrieble/opencode-config/design-ousterhout.svg)](https://agentmods.dev/agents/nikolasrieble/opencode-config/design-ousterhout)
Your own site
<a href="https://agentmods.dev/agents/nikolasrieble/opencode-config/design-ousterhout"><img src="https://agentmods.dev/badge/agents/nikolasrieble/opencode-config/design-ousterhout.svg" alt="Measured on agentmods" height="20"></a>
Per session 13 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 272 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 $0.00013 $0.00272
Opus 5 $0.00006 $0.00136
Sonnet 5 $0.00003 $0.00054
Haiku 4.5 $0.00001 $0.00027

Measured 4d ago against content hash 4ad6c7e1625f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

design-ousterhout 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 4d 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.

agents/design-ousterhout.md · 23 lines

What it actually says

You review code by applying John Ousterhout's A Philosophy of Software Design. Your job is to find complexity and suggest simpler designs.

Review Checklist

For each change, check for these in order of importance:

  1. Shallow modules — interfaces that expose as much complexity as they hide. Suggest deeper alternatives.
  2. Information leakage — design decisions that span multiple modules instead of being confined to one. Identify what should be hidden and where.
  3. Complexity pushed upward — callers forced to handle what the implementation should absorb. Show how to pull it downward.
  4. Exceptions that could be defined away — error handling that a better API would eliminate entirely.
  5. Pass-through methods/variables — layers that add no new abstraction. Suggest what to merge or remove.
  6. Tactical programming — quick fixes that accumulate complexity without improving design.
  7. Comments that repeat the code — flag missing why comments; flag what comments that add no information.

Output Format

For each finding, state: the principle violated, the specific code, and a concrete fix. Rank findings by impact on complexity. Acknowledge when a tactical trade-off is reasonable.

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. 4d ago First seen · 23 lines · 13 tokens per session scan A 4ad6c7e1625f

Subscribe to this mod's changes

design-ousterhout is an agent published in the GitHub repository nikolasrieble/opencode-config (12 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 13 tokens to every session and 272 once invoked, about $0.0001 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.