context-degradation

name	context-degradation
description	Token-range severity zones (Green/Yellow/Orange/Red/Critical) with detection checklist, early warning indicators, and corrective routing actions for context window degradation
version	1.2.0
category	Performance & Optimization
agents	["context-compressor","planner","router"]
user_invocable	true
invoked_by	both
tools	["Read","Write","Skill"]
tags	["context","tokens","degradation","compression","performance","thresholds"]
best_practices	["Check at every phase boundary, not just when problems appear","Treat 2+ early warning indicators as one zone higher","Spawn fresh subagent rather than continuing in critical zone"]
error_handling	graceful
verified	true
lastVerifiedAt	"2026-03-01T00:00:00.000Z"
source	builtin
trust_score	100
provenance_sha	0218e724e27c08a5

Context Degradation Monitor

Detects context window degradation and prescribes corrective actions before accuracy drops.

Severity Zones

Thresholds are expressed as a percentage of the context window budget. For a 200K window, Claude Code's auto-compact fires at ~187K (~93.5%, i.e., contextWindow - 13K).

Zone	Usage %	~Tokens (200K)	Status	Action
Green	< 65%	< 130K	Healthy	Normal operation
Yellow	65–80%	130K–160K	Caution	Begin selective compression
Orange/Red	80–90%	160K–180K	Warning	Compress aggressively; summarize completed phases; spawn fresh subagent if needed
Critical	90–93%	180K–186K	Severe	Halt complex reasoning; compress immediately; do not attempt multi-step tasks
Auto-compact	> 93%	> 186K	Imminent	Claude Code auto-compact will fire; initiate post-compact recovery (see below)

Reference: Claude Code constant AUTOCOMPACT_BUFFER_TOKENS = 13,000. Auto-compact fires at contextWindow - 13K, so for a 200K window that is 187K (93.5%). "Lost in the middle" effect: middle tokens have 20–40% lower recall past ~100K.

Early Warning Indicators

Symptoms that context degradation is affecting output quality (regardless of token count):

1. Repeated tool calls — Agent re-reads files already read in same session
2. Contradictory reasoning — Later steps contradict earlier decisions
3. Missing prior context — Agent "forgets" task scope or constraints stated at session start
4. Over-explanation — Agent re-explains concepts already established
5. Stale references — Agent references file paths or task IDs that were resolved earlier

If 2+ indicators are present, treat as one zone higher than token count suggests.

Corrective Routing by Zone

Yellow (65–80%):

• Invoke Skill({ skill: 'context-compressor' }) at the current phase boundary
• Remove completed phase content from active context