synthesis-model-tiers

synthesis-model-tiers is a skill for Claude Code, Codex from synthesisengineering/synthesis-skills. It costs 154 tokens per session (2,077 once invoked), scanned A, original, Apache-2.0.

A convention for choosing model roles in agent work, with labels for judgment-heavy, routine, and high-volume tasks. The labels point to current model IDs in one configuration file.

In plain words
What is it for?
Use it to select an appropriate model tier and update model mappings centrally when providers change their available models.
Why use it?
It prevents project instructions from depending on hard-coded model names that may become outdated.

Skill for Claude CodeCodex

Written for Claude Code and Codex: shipped in a Claude Code plugin, but also agents/openai.yaml present. Also seen: mentions Claude Code.

Part of the synthesis-skills plugin — 63 skills, 4 hooks shipped together

Good fit Use it to select an appropriate model tier and update model mappings centrally when providers change their available models.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/synthesisengineering/synthesis-skills/synthesis-model-tiers
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.

Any agent
npx skills add synthesisengineering/synthesis-skills --skill synthesis-model-tiers
Clone the repo
git clone --depth 1 https://github.com/synthesisengineering/synthesis-skills

Made for: Claude Code, Codex.

Or install synthesis-skills, the plugin that ships this one along with the rest of its 63 skills, 4 hooks.

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 synthesis-model-tiers

README.md
[![agentmods](https://agentmods.dev/badge/skills/synthesisengineering/synthesis-skills/synthesis-model-tiers/github.svg)](https://agentmods.dev/skills/synthesisengineering/synthesis-skills/synthesis-model-tiers)
Your own site
<a href="https://agentmods.dev/skills/synthesisengineering/synthesis-skills/synthesis-model-tiers"><img src="https://agentmods.dev/badge/skills/synthesisengineering/synthesis-skills/synthesis-model-tiers/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for synthesis-model-tiers

Your own site · 80×15
<a href="https://agentmods.dev/skills/synthesisengineering/synthesis-skills/synthesis-model-tiers"><img src="https://agentmods.dev/badge/skills/synthesisengineering/synthesis-skills/synthesis-model-tiers.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 154 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,077 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00154 $0.02077
Opus 5 $0.00077 $0.01038
Sonnet 5 $0.00031 $0.00415
Haiku 4.5 $0.00015 $0.00208

Measured 12d ago against content hash 9fe259788452, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

synthesis-model-tiers 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 12d 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.

skills/synthesis-model-tiers/SKILL.md · 93 lines

How it starts

The opening of the file, as written. The whole thing — 93 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Synthesis Model Tiers

A tiny convention that keeps model names out of everything except one file.

Skills, project context files, agent memory, and standing instructions reference role labels; the labels resolve to current model identifiers in tiers.yaml. When a vendor ships a new generation, one file changes and every consumer is current.

The three roles

Role Use for Character
judgment Judgment calls, novel patterns, skill/script authorship, cross-system changes — anywhere being wrong is expensive The most capable model you can afford
routine Routine rule-following execution: daily sweeps, mechanical runs, well-templated work The balanced default
bulk High-volume, low-stakes work: classification at scale, summarization drips The cheapest adequate option

Three roles, deliberately — even when a vendor's ladder has four or five rungs. Roles describe the work, not the vendor's catalog.

Choosing a role: diagnostic difficulty, not apparent size

The most common misroute is sending a small-sounding task to a cheap tier. Size is not the variable. Whether the cause is known is the variable.

  • Cause known → the specification is settled and the work is execution: apply this rename, run this suite, add this row, reformat these files. This is routine or bulk.
  • Cause unknown → the work is diagnosis, whatever its apparent size. Anything phrased as a symptom — "X isn't working," "this broke," "why is it doing that," "the file won't open" — is a differential over a chain of candidate causes. Cost scales with the search, not with the fix. This is judgment even when the subject is one file.

Cheap reasoning on a diagnosis does not return a smaller correct answer. It takes the first plausible branch and commits — and the confidence is what gets the wrong answer written, committed, and pushed.

Three properties force judgment regardless of how small the request sounds. Any one is sufficient:

Read the full file on GitHub · 93 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 12d ago First seen · 93 lines · 154 tokens per session scan A 9fe259788452

Subscribe to this mod's changes

synthesis-model-tiers is a skill published in the GitHub repository synthesisengineering/synthesis-skills (19 stars, last pushed today), licensed Apache-2.0. It adds 154 tokens to every session and 2,077 once invoked, about $0.0008 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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