Rootnode Context Budget

---
name: rootnode-context-budget
description: >-
  Analyzes Claude Project context budget using the two-pool architecture:
  knowledge files (~66,500 token RAG threshold) vs. threshold-exempt overhead.
  Two modes: Quick Diagnostic and Full Budget Audit. Use when user says "check
  my context budget," "how much context am I using," "is my project too big,"
  "optimize my token usage," "tier my files," "optimize for RAG," "improve
  retrieval quality," "should I keep compressing," "am I over-compressing,"
  "should I accept RAG mode." Also trigger on context pressure symptoms: "Claude
  forgets my instructions," "responses getting generic," "content not found in
  my knowledge files." Also use when a project audit scores Knowledge
  Architecture ≤ 3. Do NOT use for content placement decisions (use
  rootnode-memory-optimization if available), full project audits (use
  rootnode-project-audit if available), or behavioral tuning (use
  rootnode-behavioral-tuning if available). Opus recommended; non-Opus models
  may produce less complete analysis.
license: Apache-2.0
metadata:
  author: rootnode
  version: "5.0"
  original-source: "root_OPTIMIZATION_REFERENCE.md"
---

# Context Budget Analysis

> **Calibration:** Tier 3, Opus-primary. See repository README for model compatibility.

Analyze Claude Project context budget health. Determine operating mode (full-context vs. retrieval). Produce tiered file placement recommendations with a strategy matched to the project's growth trajectory, work-phase timing, and content routing needs.

## Important

**Token estimates are inherently approximate.** Always label token counts as "estimated" and note a ±15% margin. Never state a precise token count as fact. Use `ls -la /mnt/project/` for byte counts and divide by 4 for rough token estimates.

**Evaluate files objectively.** Users may resist demoting files they authored or consider important. Score every file on the six dimensions regardless of stated preferences. If a file scores as Tier 3, say so clearly.

**Do not assume full-context is always the goal.** With a ~66,500 token ceiling, many legitimate projects operate in retrieval mode. Assess the user's workload pattern before prescribing optimization strategy.

**Skills and MCPs cannot trigger RAG.** Do not recommend reducing Skills or disconnecting MCPs to recover knowledge file headroom. The two budget pools are independent for threshold purposes.

**Context quality degrades with total context size, not just at limits.** Even with tokens remaining, every token of overhead reduces the model's attention budget. Minimizing overhead improves output quality on every turn.

**Compression has a quality floor.** Not all content is equally compressible. Classify content type before recommending compression depth. See `references/compression-execution.md` for the Content-Type Classification (Type A prose vs. Type B precision reference) and structured off-ramps when compression stalls.

**Optimize for where the project is going, not just where it is.** A plan that restores full-context mode for one session before the next file addition pushes it back into RAG is a cleanup, not a strategy. Always assess growth trajectory before producing an optimization plan.

## Model requirements

This Skill performs per-file evaluation against the six File Evaluation Dimensions, growth trajectory analysis, content routing decisions, and phased optimization planning with compression safeguards. Opus is recommended, with effort set to `high` or `xhigh` when the deployment context allows it. On Opus at default Adaptive effort, per-file evaluation and compression quality judgment may compress — set effort higher for intelligence-sensitive audits.

On non-Opus models (Sonnet 4.6, Haiku 4.5 with extended thinking enabled), expect compressed per-file evaluation, surface-level tier recommendations, and reduced synthesis across the growth trajectory. Quick Diagnostic mode degrades less than Full Budget Audit mode. The Skill will execute and produce correctly-shaped output; users should weight findings accordingly. Haiku without extended thinking is not a supported deployment target for this Skill.

## Core Concepts

### Operating Modes

Claude Projects operate in one of two modes:

- **Full-context mode:** All knowledge files loaded into context every turn. Default when total knowledge file tokens are under the threshold.
- **Retrieval mode (RAG):** Knowledge files searched via `project_knowledge_search`; only relevant chunks loaded per turn. Activates when knowledge files exceed the token threshold.

**Detection:** Check whether `project_knowledge_search` is present in available tools. If present, retrieval mode is active. The "Indexing" label in the project UI files panel is also a visible indicator.

### The Two-Pool Budget Architecture

| Budget Pool | Allocation (200K window) | Contents | RAG Impact |
|---|---|---|---|
| Knowledge file budget | ~66,500 tokens (~33%) | Knowledge files only (all types: .md, .pdf, .docx, .xlsx, .csv, .txt, images, GitHub repos) | Exceeding triggers RAG |
| Conversation budget | ~133,500 tokens (~67%) | Platform overhead, Skills, MCPs, CI, Memory, preferences, conversation, responses | Cannot trigger RAG |

**Key implication:** Adding Skills, connecting MCPs, or expanding Custom Instructions cannot trigger RAG mode. Conversely, reducing them cannot recover knowledge file headroom. The two pools are independent.

### Token Estimation

Estimate knowledge file tokens: run `ls -la /mnt/project/` for byte sizes, divide each by 4, sum. Compare against the ~66,500 token threshold.

Conversion rates: English prose ≈ 4 characters/token. Structured content (XML, code, tables) ≈ 3.25 characters/token. Mixed markdown ≈ 3.75 characters/token. Estimates are ±15% per file, ±10% for project totals.

**Important:** Include ALL knowledge file sources: uploaded files (all types), GitHub-connected repositories, and any other connected content sources.

### Threshold-Exempt Overhead

Skills, MCPs, and other non-knowledge-file components are threshold-exempt. They affect conversation runway and attention quality but cannot trigger RAG. Key overhead sources: platform system prompt (~20–25K tokens), Custom Instructions (bytes ÷ 4), Memory (typically 500–3K tokens).

**MCP loading modes:** MCP overhead varies dramatically by loading mode. Deferred/load-as-needed (the claude.ai default) adds ~40–60 tokens per connector via a lightweight catalog plus ~5–7K flat for the deferred infrastructure — ~85% less than always-loaded mode (~3K–15K per connector). When the loading mode is unknown, note the estimate as a range and flag the uncertainty. See `references/compression-execution.md` for detailed overhead estimation.

Estimated conversation runway (assumes deferred MCP loading): lean project ~105K–110K tokens, moderate ~95K–105K, typical (6–8 MCPs, 15+ skills) ~85K–100K, heavy (always-loaded MCPs) ~50K–80K.

### Context Window Sizes by Plan

| Plan | Context Window | Knowledge File Ceiling |
|---|---|---|
| Pro / Max / Team | 200K tokens | ~66,500 tokens (empirically measured) |
| Enterprise | 500K tokens | ~165,000 tokens (estimated at 33%, untested) |
| API | 1M tokens (GA for Opus 4.6, Sonnet 4.6) | User-controlled (no platform RAG) |

### Operating Tiers

| Tier | Knowledge File Tokens | Status |
|:----:|----------------------|--------|
| 1 | Under ~30K | Comfortable headroom. Focus on structural quality. |
| 2 | ~30K–50K | Moderate. Optimization beneficial but not urgent. Monitor growth. |
| 3 | ~50K–66K | Approaching threshold. Proactive optimization recommended. |
| 4 | ~66K–500K | Retrieval mode. Optimize for recovery (if near) or retrieval quality. |
| 5 | Over ~500K | Heavy retrieval. Optimize for retrieval quality. Surface API deployment for cross-document synthesis workloads. |

File count is not a factor in RAG activation. Optimize file count for content organization and retrieval quality.

### Context Pressure vs. RAG Switching

Two independent mechanisms. RAG switching is project-level and static (knowledge files exceed threshold). Context pressure is conversation-level and dynamic (conversation approaches 200K limit). A project can experience both, either, or neither.

Diagnostic shortcuts: "Claude forgot my instructions" → context pressure OR RAG (behavioral rules not retrieved). "Claude can't find content in my files" → RAG (content not retrieved) OR context pressure (compacted). "Responses getting shorter/weaker" → context pressure.

In full-context mode, compaction summarizes conversation history but leaves knowledge files intact. In retrieval mode, knowledge files load fresh each turn via search (not subject to compaction) but conversation history still compacts.

### Placement Tiers

Files are classified into three tiers based on six evaluation dimensions (see `references/evaluation-rubric.md` for detailed scoring criteria):

- **Tier 1 — Must Keep:** High cross-reference density, behavioral content, high query frequency, severe degradation if absent.
- **Tier 2 — Optimize or Relocate:** Moderate scores. Candidates for compression, relocation, or restructuring.
- **Tier 3 — Archive or Remove:** Low scores. Stale, rarely consulted, duplicated, or retrievable on demand.

## Mode 1: Quick Diagnostic

Fast health check. Answers: Is this project at risk? What operating mode is it in? What's the right optimization strategy?

**When to use:** Quick questions about context budget health — "am I in danger?", "how big is my project?", "is my project too big?"

### Pipeline

**Step 1 — Assess project goals and use pattern.** Before calculating budgets, understand how the project is used: primary query pattern (cross-document synthesis vs. single-document retrieval), session pattern (short targeted vs. long working), content growth trajectory (stable vs. actively growing), and upcoming work phases (what's the next 1–2 quarters of work).

This determines whether full-context or optimized retrieval better serves the project. Cross-document synthesis + short sessions → full-context strongly preferred. Single-document queries → retrieval mode appropriate. Actively growing → design for retrieval from the start.

**Step 2 — Detect operating mode.** Check for `project_knowledge_search` in available tools.

**Step 3 — Inventory.** Run `ls -la /mnt/project/`. Record file names, byte sizes, estimated tokens. Count files.

**Step 4 — Calculate budget.** Sum estimated knowledge file tokens. Compare against ~66,500. Classify into operating tier (1–5). Estimate conversation runway separately (200K − platform overhead − knowledge files (if full-context) − threshold-exempt overhead). Determine MCP loading mode before estimating overhead.

**Step 5 — Assess feasibility (retrieval mode only).** Calculate gap. Quick-scan for available reductions (Tier 3 candidates, behavioral content in knowledge files, compressible files). Factor in growth trajectory — will projected additions re-cross the threshold? Classify: Recovery Achievable / Borderline / Not Feasible.

**Step 6 — Deliver.** Output adapts to operating mode and feasibility:

```
Context Budget Status: Tier [N]
— Knowledge files: ~[X]K tokens across [M] files
— Headroom / Gap: ~[H]K [remaining / over] vs. ~66.5K threshold
— MCP loading mode: [deferred / always-loaded / unknown]
— Conversation runway: ~[R]K tokens estimated
— Approximate session depth: [S] substantive turns

[If retrieval mode: Recovery verdict — Achievable / Borderline / Not Feasible]
[If Tier 2+: top risk factor and recommended next step]
[If growth trajectory identified: note projected ceiling]
```

Quick Diagnostic does NOT evaluate individual files, produce per-file tier classifications, build dependency graphs, run the RAG Quality Checklist, model growth trajectory in detail, or produce phased optimization plans.

## Mode 2: Full Budget Audit

Comprehensive analysis producing per-file evaluations, growth trajectory, work-phase heat map, content routing assessment, and a phased optimization plan.

**When to use:** Detailed analysis — "audit my context budget," "which files should I keep?", "help me reduce my knowledge file size," "tier my files," "improve my retrieval quality."

### Pipeline

**Step 1 — Assess project goals and use pattern.** Same as Quick Diagnostic Step 1, but probe deeper: identify specific upcoming work phases by name (e.g., "CRM build sprint," "website rebuild," "campaign launch") and their approximate timing.

**Step 2 — Inventory and estimate.** List all knowledge files with estimated token counts. Include all file types and GitHub repos. Estimate threshold-exempt overhead separately (determine MCP loading mode first). Produce the context budget breakdown showing both pools.

**Step 3 — Evaluate each file.** Score every knowledge file on six dimensions (see `references/evaluation-rubric.md`). Ground every score in specific evidence. Additionally, classify each file's content using both frameworks: Type A/B distribution (compression depth — see `references/compression-execution.md`) and Category 1–4 classification (storage routing — see `references/content-routing.md`).

| Dimension | What It Measures |
|-----------|-----------------|
| Cross-Reference Density | How many other files or CI sections reference this file |
| Behavioral vs. Referential | Whether the file contains rules/instructions or reference information |
| Query Frequency | How often this file is consulted across typical conversations |
| Degradation Severity | What breaks or degrades if this file is absent |
| Token Cost | Size relative to total budget — absolute and proportional |
| Cross-File Dependency Density | How much this file depends on content in other files |

**Step 4 — Growth Trajectory Assessment.** Before producing any optimization plan, model where the project is heading:

1. **Planned additions:** What files, content, or capabilities are expected in the next 1–2 quarters? Estimate token counts.
2. **Active growth files:** Which files are actively growing (campaign content, competitor intelligence, expanding guides) vs. stable reference?
3. **Seasonal rotation:** Which files have temporal decay (campaign playbooks, seasonal content) that will naturally free budget?
4. **Planning ceiling:** Current tokens + projected additions + projected growth = the number the optimization must create headroom beneath, not just the current threshold.

If the user does not volunteer growth information and it cannot be inferred from project content, ask.

**Step 5 — Work-Phase Heat Map.** Map file relevance to upcoming work phases:

1. Identify the user's next 2–3 major project phases from Step 1.
2. For each file, assess: HOT (primary working reference during this phase), WARM (occasionally consulted), or COLD (not needed).
3. Use the heat map to time optimization actions — compress files during their cold phase, protect hot-phase files from disruption.

**Step 6 — Build the dependency graph.** Map explicit references between files. Map CI references to each file. Identify clusters, hub files, and mutual dependencies.

**Step 7 — Classify tiers.** Apply the tier decision matrix from `references/evaluation-rubric.md`. When dimension scores conflict, explain tiebreaker reasoning.

**Step 8 — Run feasibility assessment.** Same methodology as Quick Diagnostic Step 5, but with precise per-file data. Factor in the planning ceiling from Step 4 — optimize against the projected total, not just the current total.

**Step 9 — RAG Quality Assessment (retrieval mode only).** Run the seven-item RAG Quality Checklist from `references/evaluation-rubric.md`. Score each item pass/fail with evidence. Prescribe targeted fixes for failures.

**Step 10 — Produce the phased optimization plan.** For each Tier 2 and Tier 3 file, recommend a specific action:

- **Archive:** Remove from active knowledge files. Content outdated or not consulted.
- **Remove redundancy:** Delete duplicated or superseded content sections.
- **Compress:** Reduce token count. Include content-type distribution (Type A% / Type B%). Set conservative targets for Type B-heavy files. See `references/compression-execution.md`.
- **Relocate to CI/Memory/Skill:** Move behavioral rules to CI, orientation facts to Memory, standalone methodologies to Skills.
- **Data split (Category 3):** Migrate structured reference data to an external store via MCP. See `references/content-routing.md` for the full data split pattern, MCP infrastructure assessment, and fallback guidance.
- **Merge:** Combine related files to reduce cross-file dependency overhead.
- **Flag structural opportunity (Category 4):** When structured data would benefit from a queryable store but no MCP infrastructure is available, note the opportunity in the plan.

**Order by composite priority**, not raw token savings:
1. **Strategic constraints** — protect files entering their hot phase; defer optimization of files the user needs this week.
2. **Effort level** — archives and redundancy removal before compression before restructuring before data splits.
3. **Disruption cost** — cold-phase files before hot-phase files (reference the Work-Phase Heat Map).
4. **Token yield** — higher savings as tiebreaker when effort and disruption are equal.

**Structure the plan in three phases:**

**Phase 1 — Zero-Effort (execute now):** Archives, redundancy removal, section deletion. No rewriting required. Include cumulative savings, projected tier, and what the headroom enables.

**Phase 2 — High-Yield Optimization (execute during next cold phase):** Largest optimization targets that are currently cold. Includes both compression of Category 2 content AND data splits for Category 3 content. Include cumulative savings, projected tier, and phase transition timing referencing the heat map.

**Phase 3 — Reserve (execute when needed):** Moderate targets to deploy if growth exceeds projections or Phase 2 savings are lower than estimated. Include projected impact.

**Step 11 — Validate.** Verify the plan does not remove content critical to core function. If full-context recovery was the target, verify projected post-optimization state is within threshold AND within the planning ceiling. Verify compression of Type B content has proportionate savings-to-risk ratio.

### Output Format

```
# Context Budget Audit: [Project Name]

## Budget Overview
[Two-pool breakdown. Operating tier. Mode status.]

## Use-Case Assessment
[Query pattern, session pattern, growth trajectory, upcoming phases.]

## Growth Trajectory
— Planned additions: [files with estimated token counts]
— Active growth files: [files and projected growth]
— Seasonal rotation: [files with known expiration dates]
— Planning ceiling: ~[current + projected]K tokens
— Required headroom: ~[planning ceiling − threshold]K tokens

## Work-Phase Heat Map
| File | Phase 1: [name] | Phase 2: [name] | Phase 3: [name] |
|---|---|---|---|
| [file] | HOT | WARM | COLD |
...
Compression timing: [which files to compress now vs. defer]

## Feasibility Assessment
[Recovery verdict against planning ceiling, not just current state]

## File Evaluation
[Per-file table: file name, estimated tokens, six dimension scores,
content-type (A/B%), content category (1–4), placement tier, key evidence]

## Dependency Graph
[File-to-file reference map. Hubs, clusters, mutual dependencies.]

## Content Routing Summary
[Per file with mixed categories:]
— Category 1 (behavioral): [X]% → Relocate to CI/Memory
— Category 2 (strategic): [Y]% → Retain in KF (compress Type A)
— Category 3 (structured, MCP available): [Z]% → Migrate to [store]
— Category 4 (structured, no MCP): [W]% → RAG-optimize (flag opportunity)
— Net KF reduction: ~[S]K tokens

## RAG Quality Assessment (retrieval mode only)
[Seven-item checklist with pass/fail and fixes.]

## Optimization Plan

### Phase 1 — Zero-Effort [execute now]
[Actions. Cumulative savings: ~XK. Projected tier: N. Headroom: ~HK.]

### Phase 2 — High-Yield Optimization [execute during Phase [name]]
[Actions including data splits. Cumulative savings: ~XK. Projected tier: N.]

### Phase 3 — Reserve [execute if needed]
[Actions. Projected impact if deployed.]

## Post-Optimization Projection
[Projected state after each phase. Verification against planning ceiling.]
```

## Content Classification Framework

Knowledge file content falls into four categories that determine the optimal storage and access pattern. Type A/B classification (see `references/compression-execution.md`) determines compression depth for content staying in knowledge files. Category 1–4 classification determines whether content should stay in knowledge files at all. Apply both: Type A/B for compression, Category 1–4 for routing.

- **Category 1 — Behavioral/Instructional:** Rules, constraints, workflow instructions. Must be in always-present layers (CI, Memory, Tier 1 KF). Never place behind a tool call.
- **Category 2 — Strategic/Analytical:** Positioning analysis, opportunity matrices, design rationale. Benefits from passive awareness. Keep in knowledge files; compress Type A portions.
- **Category 3 — Structured Reference Data WITH MCP:** Tabular data with natural key-value structure where a queryable store is available via MCP. Strictly better than RAG for this content type — deterministic retrieval, structural integrity, permanent budget relief. See `references/content-routing.md` for the data split pattern.
- **Category 4 — Structured Reference Data WITHOUT MCP:** Same data types as Category 3, but no external store available. RAG-optimize as fallback. Flag the structural opportunity for future resolution.

For detailed guidance on each category, MCP infrastructure assessment, data split execution, fallback patterns, and retrieval quality tradeoffs, read `references/content-routing.md`.

### API Deployment as Alternative Architecture

When knowledge file requirements exceed ~500K tokens AND the use case requires cross-document synthesis across that content, surface API-based deployment. Context window: 1M tokens (Opus 4.6, Sonnet 4.6) — GA at standard per-token pricing. Tradeoffs: per-token billing on massive inputs, higher latency (30–60+ seconds), context rot at scale, full stack ownership (conversation management, retrieval, memory — all custom). API deployment is a different product architecture, not a casual upgrade. Recommend only when knowledge volume exceeds ~500K tokens, cross-document synthesis is required, and the user has engineering capacity for the integration. Do NOT recommend for projects that simply exceed ~66,500.

## Empirical Threshold Measurement

When estimates are insufficient — borderline projects, unexpected RAG activation, post-platform-update verification — direct measurement is the most reliable method.

**Quick method (±1,000 tokens):** Note current knowledge file byte total. Add files until "Indexing" appears (if full-context) or remove until it disappears (if retrieval). Boundary in bytes ÷ 4 ≈ threshold in tokens.

**Precision method (±50–100 tokens):** Requires pre-sized calibration files. See the Context Budget Calibration Lab methodology.

**Observable RAG indicators:** "Indexing" label in project UI files panel (visible without starting a conversation). `project_knowledge_search` tool present in available tools (definitive).

## When to Use This Skill

Use this Skill when:
- The user asks about context budget health, token usage, or project size
- The user reports context pressure symptoms: forgetting instructions, generic responses, inconsistency, content not found
- A project audit scores Knowledge Architecture ≤ 3 and the issue appears budget-related
- The user wants to understand retrieval mode or optimize for RAG quality
- The user is mid-compression and asks whether to continue or accept RAG mode

Do NOT use when:
- Content placement across layers — use rootnode-memory-optimization if available
- Overall project architecture quality — use rootnode-project-audit if available
- Claude behavioral tendencies — use rootnode-behavioral-tuning if available
- Building or revising a prompt — this Skill analyzes context economics, not prompt quality

## Troubleshooting

**User reports context pressure but project is Tier 1.** The issue is structural, not budget-related. Recommend rootnode-project-audit or rootnode-anti-pattern-detection if available.

**Feasibility says "Achievable" but gap is very tight.** Present as Borderline. Build in a 10–15% buffer. Check growth trajectory — if planned additions would re-cross the threshold within a quarter, the recovery is temporary and the plan should account for it.

**User wants full-context but project is Tier 5.** Be direct: full-context recovery would remove core functionality. Optimize for retrieval quality. If cross-document synthesis at >500K tokens is required, surface the API path.

**Behavioral content in knowledge files (retrieval mode).** Highest-impact retrieval quality fix. Behavioral rules in knowledge files are intermittent in RAG mode. Move to CI or Memory. Recommend rootnode-behavioral-tuning if available for countermeasure calibration.

**Memory carrying reference-depth content.** Most common cross-project context issue. When Memory exceeds ~2K tokens, recommend rootnode-memory-optimization if available.

**Unexpected RAG activation with no knowledge file changes.** Check GitHub repo growth, uncounted file types (PDFs, images, DOCX). If no changes, platform update may have shifted threshold — recommend empirical measurement.

**MCP overhead estimates seem too high.** Check whether connectors use deferred loading. Prior estimates assuming always-loaded overstate overhead by 3–5x. Recalculate with correct loading mode.

**Compression has stalled or diminishing returns.** Run the Diminishing Returns Checkpoint from `references/compression-execution.md`. If remaining targets are predominantly Type B, present the RAG-Acceptance Decision Point. Do not compress precision reference content to reach a threshold.

**User asks "should I accept RAG mode?"** Direct trigger for the RAG-Acceptance Decision Point in `references/compression-execution.md`. Determine whether optimization has been attempted first — if not, run a Quick Diagnostic before accepting.

**Optimization plan restores threshold but growth will re-cross it.** This is the Gap 1 scenario. The plan targeted the current state, not the planning ceiling. Re-run Step 4 (Growth Trajectory) and revise the plan against the projected total. The user needs a strategy, not a cleanup.

**File contains mixed structured + strategic content.** Apply the Content Classification Framework. Split the file conceptually: strategic/analytical portions stay in the knowledge file, structured/tabular portions are data split candidates (Category 3) or RAG-optimization targets (Category 4). See `references/content-routing.md`.

## Reference Files

- **`references/evaluation-rubric.md`** — Read when performing a Full Budget Audit (Mode 2, Steps 3 and 7). Contains: six evaluation dimensions with detailed scoring criteria, tier decision matrix with tiebreaker logic, compression risk assessment, and seven-item RAG Quality Checklist.

- **`references/compression-execution.md`** — Read when recommending or executing compression. Contains: Content-Type Classification (Type A/B), compression tiers (safe/moderate/aggressive), MCP overhead estimation detail, sequencing rules, Diminishing Returns Checkpoint, RAG-Acceptance Decision Point, and budget-constrained project guidance.

- **`references/content-routing.md`** — Read when a file contains structured reference data or mixed content categories. Contains: Category 1–4 detailed descriptions, Data Split Pattern (Category 3) with MCP infrastructure assessment and platform dependency considerations, fallback pattern, retrieval quality tradeoff, and Structural Opportunity Flag (Category 4).