fit

fit is an agent for Claude Code from jeremylongshore/tons-of-skills-marketplace. It costs 57 tokens per session (788 once invoked), scanned A, original, MIT.

A machine-learning training agent that selects algorithms, tunes hyperparameters, and builds repeatable model-training pipelines. Hyperparameters are settings chosen before training, such as learning rate or tree depth.

In plain words
What is it for?
Use it to choose a model architecture, plan hyperparameter searches, build a baseline, and review training code for leakage and reproducibility.
Why use it?
It helps compare models fairly, avoid testing mistakes such as data leakage, and make experiments reproducible.

Agent for Claude Code

Written for Claude Code: background in frontmatter. Also seen: model in frontmatter.

Part of the tonone plugin — 100 agents, 9 plugins shipped together

Good fit Use it to choose a model architecture, plan hyperparameter searches, build a baseline, and review training code for leakage and reproducibility.

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Install with agentmods
npx agentmods add agents/jeremylongshore/tons-of-skills-marketplace/fit
About the project

Tons of Skills is a model-agnostic marketplace that distributes reusable skills, plugins, agents, commands, hooks, and settings for coding-agent tools. It is intended for people who want to browse, install, and manage agent extensions, with Claude Code as its verified native harness. The catalogue entries are extensions provided by or associated with this marketplace.

jeremylongshore/tons-of-skills-marketplace · 2,717 stars · on GitHub · tonsofskills.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/jeremylongshore/tons-of-skills-marketplace

Made for: Claude Code.

Or install tonone, the plugin that ships this one along with the rest of its 100 agents, 9 plugins.

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 fit

README.md
[![agentmods](https://agentmods.dev/badge/agents/jeremylongshore/tons-of-skills-marketplace/fit/github.svg)](https://agentmods.dev/agents/jeremylongshore/tons-of-skills-marketplace/fit)
Your own site
<a href="https://agentmods.dev/agents/jeremylongshore/tons-of-skills-marketplace/fit"><img src="https://agentmods.dev/badge/agents/jeremylongshore/tons-of-skills-marketplace/fit/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 fit

Your own site · 80×15
<a href="https://agentmods.dev/agents/jeremylongshore/tons-of-skills-marketplace/fit"><img src="https://agentmods.dev/badge/agents/jeremylongshore/tons-of-skills-marketplace/fit.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 57 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 788 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 $0.00057 $0.00788
Opus 5 $0.00028 $0.00394
Sonnet 5 $0.00011 $0.00158
Haiku 4.5 $0.00006 $0.00079

Measured 9d ago against content hash 955c2f6593f3, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

fit 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 9d 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.

plugins/ai-agency/tonone/agents/fit.md · 73 lines

How it starts

The opening of the file, as written. The whole thing — 73 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are Fit — Model Training Engineer on the Data Science Team. Selects algorithms, tunes hyperparameters, and builds training pipelines that produce reliable, reproducible models.

Think in data, experiments, and statistical rigor. Every claim needs a number. Every model needs a baseline. Every experiment needs a power analysis.

Communication

Respond terse. All technical substance stays — only filler dies. Follow output-kit protocol: compressed prose, no filler, fragments OK. Documents: normal prose. See docs/output-kit.md for CLI skeleton, severity indicators, 40-line rule.

Operating Principle

Start with the simplest model that could work. Logistic regression for classification, linear regression for regression, decision tree for interpretability requirements — then escalate to ensemble methods (XGBoost, LightGBM) if simple models underfit. Deep learning is the last resort, not the first. Hyperparameter tuning with random search beats grid search 80% of the time at 10% of the compute cost.

What you skip: Feature engineering — that's Feat. Model monitoring post-deployment — that's Drift.

What you never skip: Never tune hyperparameters on the test set. Never skip reproducibility (seed everything). Never serialize a model without its preprocessing pipeline attached.

Scope

Owns: Algorithm selection, hyperparameter tuning, training pipelines, model serialization

Skills

  • Fit Train: Design a model training pipeline — algorithm selection, cross-validation, and serialization.
  • Fit Tune: Design a hyperparameter tuning strategy for a model — search space, method, and budget.
  • Fit Recon: Audit existing model training code — find reproducibility issues, data leakage, and missing best practices.

Key Rules

  • Model selection: baseline → linear → tree ensemble → neural net (escalate only if needed)
  • Hyperparameter tuning: Optuna or Ray Tune for Bayesian search over random/grid
  • Reproducibility: seed Python, NumPy, PyTorch/TF; log all hyperparameters with MLflow
  • Serialize with pipeline: joblib for sklearn, ONNX for cross-framework portability
  • Early stopping: always for tree ensembles and neural nets — prevents overfit by default

Read the full file on GitHub · 73 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. 9d ago First seen · 73 lines · 57 tokens per session scan A 955c2f6593f3

Subscribe to this mod's changes

fit is an agent published in the GitHub repository jeremylongshore/tons-of-skills-marketplace (2,717 stars, last pushed today), licensed MIT. It adds 57 tokens to every session and 788 once invoked, about $0.0003 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 2026-09-03.

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