Ai Context Engineer

AI Context Engineer

When to Use

• Designing what enters the model context each turn
• Optimizing cost/latency via context strategy and token budgeting
• Building context pipelines for agents (prefix, retrieval, history, user input)
• Implementing summarization, compaction, or rolling history
• Debugging context-related failures (lost instructions, overflow, distraction, ignored constraints)
• Choosing delimiters, XML blocks, or structured context formats

When NOT to Use

• Persistent memory store design or long-term recall architecture → ai-memory-developer
• Full RAG ingest/chunk/embed/index pipelines → ai-engineer
• AI org operations, release governance, or SLOs → ai-lead-ops
• Structured token/cost improvement roadmaps with phased KPIs → ai-token-improvement-plan-engineer
• Commercial/enterprise AI solution architecture → applied-ai-architect-commercial-enterprise

Related skills

| Need | Skill | |---|---| | Memory stores and long-term recall | ai-memory-developer | | RAG ingest/chunk/embed | ai-engineer | | System and tool prompts | prompt-engineer | | Red-team injection via context | ai-redteam | | Cost and production SLAs | ai-lead-ops | | Token reduction program and roadmap | ai-token-improvement-plan-engineer | | Commercial/enterprise AI architecture | applied-ai-architect-commercial-enterprise | | Token efficiency research and ablations | research-engineer-scientist-tokens |

Core Workflows

1. Context budget and layout

Allocate tokens (example 128k window):

| Block | Budget % | Priority | |---|---|---| | System policy + tools | 15–25% | Fixed, never truncated | | Retrieved docs / memory | 30–45% | High, reranked | | Conversation history | 25–40% | Compress oldest first | | User current message | 5–10% | Never drop |

Use explicit XML/markdown sections: `, , , , `.

See references/context_layout.md for templates and delimiter rules.

2. History management

| Strategy | When | |---|---| | Full recent window | Short chats, high-stakes instructions in last N turns | | Rolling summary | Long sessions; summarize every K turns | | Anchor messages | Pin system + key user constraints; summarize middle | | Structured state | Replace chat with JSON task state for agents |

Preserve: user goals, constraints, unresolved tool errors, pending confirmations.

See references/history_compression.md for summarization prompts and pitfalls.

3. Retrieval into context

1. Query from user message + state summary
2. Retrieve candidates (RAG chunks, memories, tool outputs)
3. Deduplicate overlapping passages
4. Order by relevance; add source labels
5. Truncate with sentence boundaries; show "[truncated]" when cut

See references/retrieval_packing.md for packing algorithms and citation format.

4. Caching and prefetch

• Cache stable prefix (system + tools) where provider supports prompt caching
• Prefetch retrieval while user types (optional)
• Invalidate cache on prompt version change

See references/caching_prefetch.md for provider notes and invalidation.

5. Debug context failures

| Symptom | Likely cause | Fix | |---|---|---| | Ignored instruction | Buried in middle / summarized away | Move to system or last user turn | | Hallucinated doc | Weak retrieval | Raise threshold; require citation | | Overflow error | No budget enforcement | Pre-flight token count; compress | | Tool confusion | Ambiguous schemas in context | Separate tool block; shorten descriptions |

Log token counts per block in dev/staging.

See references/debugging_context.md for instrumentation checklist.

When to load references

• Layout and budgets → references/context_layout.md
• Summarization → references/history_compression.md
• RAG/memory packing → references/retrieval_packing.md
• Caching → references/caching_prefetch.md
• Debugging → references/debugging_context.md

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: daemon-blockint-tech
• Source: daemon-blockint-tech/Agentic-Enteprises-Skill
• License: MIT

Install and usage instructions live in the source repository linked above.