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name: principle-guard-the-context-window description: "Apply when context is filling up: large outputs, long files, repeated reads, fan-out planning. Route bulk to subagents; keep summaries in the main thread, not raw payloads." disable-model-invocation: true

Guard the Context Window

The context window is finite and non-renewable within a session. Every token that enters should earn its place.

Why: Context overflow degrades reasoning quality, creates compression artifacts, and halts progress. Unlike compute or time, context spent inside a session cannot be reclaimed.

Pattern:

• Isolate large payloads. Route verbose outputs, screenshots, and large documents to subagents. The main context gets summaries, not raw data.
• Don't read what you won't use. Read selectively based on relevance. If a file isn't needed for the current task, skip it.
• Keep frequently used content inline. Templates and references used on every invocation belong in the skill file, not in separate files that cost a read each time.
• Size phases and cap scope. Limit files per phase, set turn budgets, account for mechanism costs.