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AI Context Engineering – Ultimate Cheat Sheet

???? Core Principles Context Window Limited token budget (~200k tokens typical) Context = Input + Output combined Earlier tokens may be "forgotten" (lost attention) Most recent context has…

AI Context Engineering - Ultimate Cheat Sheet

???? Core Principles

Context Window

  • Limited token budget (~200k tokens typical)
  • Context = Input + Output combined
  • Earlier tokens may be “forgotten” (lost attention)
  • Most recent context has highest weight

Information Density

  • Dense, structured input > verbose
  • Use XML/JSON for complex data
  • Key info at start AND end
  • Remove redundancy ruthlessly

???? Prompt Structure

Optimal Template

<role>Expert persona</role> <task>What to do</task> <context>Background info</context> <constraints>Rules</constraints> <output_format>Structure</output_format> <examples>…</examples>

Critical Elements

  • Clear objective (single, specific)
  • Success criteria defined
  • Format requirements explicit
  • Edge cases addressed

???? Few-Shot Techniques

Example Types

  • Positive: Ideal outputs
  • Negative: What to avoid
  • Edge cases: Boundary conditions
  • Progressive: Simple → Complex

Best Practices

  • 3-5 examples optimal
  • Diverse, representative samples
  • Annotate reasoning process
  • Match target complexity

???? Chain-of-Thought

Activation Phrases

Zero-shot: “Let’s think step by step…”
“First, analyze… Then…”
“Break this down systematically”

Advanced Patterns

  • Self-Consistency: Multiple reasoning paths
  • Tree-of-Thought: Explore branches
  • Meta-prompting: Analyze prompt first

⚙️ Token Optimization

Compression Strategies

  • Use abbreviations consistently
  • Remove articles (a, an, the)
  • Prefer numerals over words
  • Use symbols: → ∴ ∵ ≈

Token Count Rules

~4 chars = 1 token
100 words ≈ 75 tokens
  • Whitespace counts
  • Code is token-expensive
  • Repeated patterns compress

???? Role & Persona Engineering

Effective Personas

Generic: “You are helpful”
Specific: “You are a senior DevOps engineer with 15 years experience in Kubernetes, known for writing clear, actionable documentation”
  • Specific expertise domain
  • Years of experience
  • Communication style
  • Known strengths/weaknesses

Multi-Agent Patterns

  • Debate: Pro vs Con roles
  • Specialist Panel: Expert consultation
  • Red Team: Adversarial review
  • Socratic: Question-driven dialogue
Analyst: {analysis} Critic: {critique} Synthesizer: {final_output}

???? Output Control

Format Specifications

  • Structured: JSON, XML, YAML
  • Length: Exact word/token count
  • Style: Tone, formality, POV
  • Constraints: No speculation, cite sources

Validation Triggers

“Before responding, verify:
✓ All claims sourced
✓ Format matches schema
✓ Edge cases handled”

????️ Context Window Management

Prioritization Strategies

  • Recency: Latest messages matter most
  • Relevance: Semantic similarity search
  • Importance: Tag critical information
  • Summarization: Compress old context
Priority_Score = (Recency × 0.3) + (Relevance × 0.5) + (Importance × 0.2)

Memory Patterns

  • Sliding Window: Keep N recent turns
  • Hierarchical: Summary + recent detail
  • Retrieval: Vector DB + current context
  • Compression: Distill multi-turn to summary
System: {permanent_instructions} Summary: {condensed_history} Recent: {last_3_turns} Current: {user_message}

???? RAG (Retrieval)

Context Injection

  • Embed retrieved docs with metadata
  • Source attribution required
  • Chunk size: 200-500 tokens optimal
  • Include relevance scores

Quality Signals

<source confidence=”0.89″>
<metadata>Updated: 2024-01</metadata>
{retrieved_content}
</source>

???? Advanced Methods

Self-Reflection

1. Generate initial response 2. Critique: “What’s wrong?” 3. Refine based on critique 4. Repeat if needed

Constitutional AI

  • Embed principles in system
  • Self-critique against rules
  • Revision loops

???? Semantic Control

Embedding Strategies

  • Similar examples cluster together
  • Use for dynamic few-shot selection
  • Semantic search > keyword match
  • Rerank by similarity score

Distance Metrics

Cosine Similarity Euclidean Dot Product

⚠️ Common Pitfalls & Solutions

❌ Vague Instructions

Bad: “Write something good”
Good: “Write a 500-word technical blog post for developers explaining OAuth 2.0 flow with code examples in Python”

❌ Conflicting Directives

Bad: “Be brief but comprehensive”
Good: “Provide a 200-word summary covering the 3 most important points”

❌ Assumed Knowledge

Bad: “Fix the bug”
Good: “The login form submits but returns 401. Here’s the code: {…}”

❌ No Format Spec

  • Always define output structure
  • Use schema/template
  • Example of desired format

❌ Ignoring Tokens

  • Monitor context usage
  • Compress when possible
  • Truncate intelligently

❌ One-Shot Hoping

  • Iterate prompts
  • Test variations
  • A/B test approaches

???? Testing & Evaluation

Evaluation Metrics

  • Accuracy: Factual correctness
  • Relevance: On-topic responses
  • Coherence: Logical flow
  • Consistency: Same input → same output
  • Completeness: All requirements met

Testing Strategies

  • Build test suite of edge cases
  • Use golden datasets
  • Temperature testing (0.0 → 1.0)
  • Automated regression tests
  • Human-in-loop validation

Quick Wins

Instant Improvements

  • ✓ Add “Let’s think step-by-step”
  • ✓ Provide 2-3 examples
  • ✓ Define output format
  • ✓ Use XML tags for structure
  • ✓ Specify desired length
  • ✓ Include validation criteria

???? Model-Specific Strategies

Claude-Specific

  • Prefers XML structure
  • Excels at long context
  • Strong with technical tasks
  • Use <thinking> tags for reasoning

GPT-Specific

  • Follows system messages strongly
  • JSON mode available
  • Function calling native
  • Sensitive to instruction order

????️ Parameters

Temperature Guide

  • 0.0-0.3: Deterministic, factual
  • 0.4-0.7: Balanced creativity
  • 0.8-1.0: Highly creative

Other Parameters

  • top_p: Nucleus sampling (0.9 typical)
  • max_tokens: Hard output limit
  • frequency_penalty: Reduce repetition

???? Security & Safety

Prompt Injection Defense

  • Sandwich user input with instructions
  • Use delimiters clearly
  • Validate output format strictly
  • Never trust user-provided “system” messages

Content Filtering

<user_input> {sanitized_input} </user_input> Respond only to legitimate requests
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