principle-guard-the-context-windowlisted

# 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. The test is per-invocation frequency: content read on every invocation goes inline; content read on some invocations gets its own file. - **Size phases and cap scope.** Limit files per phase, set turn budgets, account for mechanism costs.