principle-guard-the-context-window

principle-guard-the-context-window is a skill for Claude Code from koolamusic/claudefiles. It costs 46 tokens per session (112 once invoked), scanned A, a copy of principle-guard-the-context-window, MIT.

A method for managing the amount of text and code kept in an agent's working context. It limits each phase, sends bulky work to other agents, and keeps summaries instead of full outputs.

In plain words
What is it for?
It helps plan work in small batches, cap the number of files or turns per phase, and pass only concise findings between agents.
Why use it?
Very large or repeated inputs can crowd out useful information and reduce reasoning quality. This keeps the main conversation focused and prevents it from stopping because it is full.

Skill for Claude Code

Written for Claude Code: disable-model-invocation in frontmatter. Also seen: mentions subagents.

Part of the pstack plugin — 50 skills, 2 agents shipped together

Good fit It helps plan work in small batches, cap the number of files or turns per phase, and pass only concise findings between agents.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/koolamusic/claudefiles/principle-guard-the-context-window
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 koolamusic/claudefiles --skill principle-guard-the-context-window
Clone the repo
git clone --depth 1 https://github.com/koolamusic/claudefiles

Made for: Claude Code.

Or install pstack, the plugin that ships this one along with the rest of its 50 skills, 2 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 principle-guard-the-context-window

README.md
[![agentmods](https://agentmods.dev/badge/skills/koolamusic/claudefiles/principle-guard-the-context-window/github.svg)](https://agentmods.dev/skills/koolamusic/claudefiles/principle-guard-the-context-window)
Your own site
<a href="https://agentmods.dev/skills/koolamusic/claudefiles/principle-guard-the-context-window"><img src="https://agentmods.dev/badge/skills/koolamusic/claudefiles/principle-guard-the-context-window/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 principle-guard-the-context-window

Your own site · 80×15
<a href="https://agentmods.dev/skills/koolamusic/claudefiles/principle-guard-the-context-window"><img src="https://agentmods.dev/badge/skills/koolamusic/claudefiles/principle-guard-the-context-window.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 46 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 112 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 86% copy Near-identical to another mod 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 $0.00046 $0.00112
Opus 5.5 $0.00018 $0.00045
Sonnet 5.5 $0.00009 $0.00022
Haiku 4.5 $0.00005 $0.00011

Measured 2d ago against content hash af0b9dd70b43, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

principle-guard-the-context-window 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 2d 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

This is a copy

86% identical to principle-guard-the-context-window — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

plugins/pstack/skills/principle-guard-the-context-window/SKILL.md · 13 lines

What it actually says

Guard the Context Window

Why: Context overflow degrades reasoning quality, creates compression artifacts, and halts progress.

Pattern:

  • Size phases and cap scope. Limit files per phase, set turn budgets, account for mechanism costs.
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. 2d ago First seen · 13 lines · 46 tokens per session scan A af0b9dd70b43

Subscribe to this mod's changes

principle-guard-the-context-window is a skill published in the GitHub repository koolamusic/claudefiles (130 stars, last pushed yesterday), licensed MIT. It adds 46 tokens to every session and 112 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 86% identical to principle-guard-the-context-window, differing in 0 lines, and is treated as a copy.

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