Overview
Context engineering is an emerging concept focused on the deliberate design and management of information flow between users, applications, and AI models. Unlike established fields such as prompt engineering, context engineering is still being defined by practitioners as they work to solve the unique challenges of providing AI models with the right information at the right time.“In 2025, the models out there are extremely intelligent. But even the smartest human won’t be able to do their job effectively without the context of what they’re being asked to do… ‘Context engineering’ is the next level of prompt engineering. It is about doing this automatically in a dynamic system.” — Walden Yan, Cognition AI
The context journey
Information flows through five stages in a typical MCP system:| Stage | Description |
|---|---|
| User input | Raw information from the user (text, images, documents) |
| Context assembly | Combining user input with system context, history, and retrieved information |
| Model processing | The AI model processes the assembled context |
| Response generation | The model produces outputs based on the provided context |
| State management | The system updates its internal state based on the interaction |
Core areas of context engineering
Context engineering encompasses five areas particularly relevant to MCP:Context selection
Determining what information is relevant for a given task
Context structuring
Organizing information to maximize model comprehension
Context delivery
Optimizing how and when information is sent to models
Context maintenance
Managing state and evolution of context over time
Context evaluation
Measuring and improving the effectiveness of context
Emerging principles
Principle 1: Share context completely
Context should be shared completely between all components rather than fragmented across multiple agents or processes.Principle 2: Actions carry implicit decisions
Each action a model takes embodies implicit decisions about how to interpret context. When multiple components act on different contexts, these decisions can conflict. Practical implications:- Prefer linear processing of complex tasks over parallel execution with fragmented context
- Ensure all decision points have access to the same contextual information
- Design systems where later steps can see the full context of earlier decisions
Principle 3: Balance context depth with window limitations
As conversations grow longer, context windows eventually overflow. Effective context engineering manages the tension between comprehensive context and technical limitations.Emerging approaches
1. Context chunking and prioritization
2. Progressive context loading
3. Context compression and summarization
- Removing redundant information
- Summarizing lengthy exchanges
- Extracting key facts and decisions
- Optimizing for token efficiency
4. Layered context architecture
Some practitioners find success with context arranged in conceptual layers:| Layer | Content |
|---|---|
| Core layer | Essential information the model always needs |
| Situational layer | Context specific to the current interaction |
| Supporting layer | Additional information that may be helpful |
| Fallback layer | Information accessed only when needed |
MCP protocol design responses
The MCP protocol was designed with context challenges in mind:Context window limitations
Context window limitations
The protocol supports structured, resource-based context that can be referenced efficiently. Resources can be paginated and loaded progressively.
Relevance determination
Relevance determination
Flexible tooling allows dynamic retrieval of information based on need. Structured prompts enable consistent context organization.
Context persistence
Context persistence
Standardized session management and clearly defined interaction patterns for context evolution.
Multi-modal context
Multi-modal context
Protocol design accommodates various content types with standardized representation of multi-modal information.
Security and privacy
Security and privacy
Clear boundaries between client and server responsibilities, with local processing options to minimize data exposure.
Multi-agent architecture tradeoffs
| Concern | Multi-agent | Single-agent |
|---|---|---|
| Context fragmentation | High risk | Low risk |
| Decision consistency | Requires coordination | Naturally consistent |
| Communication overhead | High | None |
| State management complexity | High | Lower |
| Debugging difficulty | Complex | Simpler |
Measuring context effectiveness
Context engineering is still maturing, but several metrics are emerging:Input efficiency
Context-to-response ratio, token utilization, compression effectiveness
Performance
Latency impact, token economy, retrieval precision
Quality
Response relevance, factual accuracy, consistency, hallucination rate
User experience
Follow-up rate, task completion, satisfaction indicators
Experimental approach
Context engineering is still in its early stages. Recommended approach:- Establish a baseline with simple context before testing sophisticated methods
- Change one thing at a time to isolate the effect of each context change
- Combine quantitative metrics with qualitative user feedback
- Analyze failures to understand why context strategies fall short
- Consider tradeoffs between efficiency, quality, and user experience
Resources
MCP Documentation
Official MCP specification and implementation guides
Don't Build Multi-Agents
Walden Yan’s insights on context engineering principles
Building Effective Agents
Anthropic’s approach to agent development
Lost in the Middle
Research on how language models use long contexts