LLM Cheatsheet: signal words that actually matter
When you build software with LLMs, the words in your prompts are your primary steering mechanism. A single well-chosen operator word can swing accuracy by 10+ points. Formatting and structure shifts can swing output quality by up to 76 points (ZIP paper, arXiv 2502.03418).
Three categories do most of the work:
- Behavioral triggers. Verbs that tell the model how to think.
- Constraint markers. Words that rule out unwanted directions.
- Domain anchors. Single terms that pull the model into expert register.
Combine one from each. Usually 8 to 12 words. That works better than paragraphs of vague instruction.
Precision verbs (behavioral triggers)
These activate a processing mode rather than just a topic. Swapping one operator word moves output considerably. The ZIP paper found that nouns dominate importance rankings across every model tested.
| Term | What it triggers | Stronger than |
|---|---|---|
| Audit | Check against a standard; flag what fails | review (model defaults to descriptive) |
| Diagnose | Find the non-obvious root cause | explain (descriptive, not causal) |
| Steelman | Build the strongest opposing position | counter-argument (produces strawmen) |
| Critique | Find specifically what is weak | give feedback (too open) |
| Enumerate | Exhaustive list, every item | list (implies a few is fine) |
| Extract | Pull specific data, no invention | find (no structure implied) |
| Identify | Name the specific thing, skip the explanation | analyze (produces paragraphs) |
| Trace | Map a causal or ownership chain end to end | follow (no chain notion) |
| Consolidate | Merge N sources, deduping | combine (produces concatenation) |
| Synthesize | Combine threads into a novel framework | summarize (reduces, does not create) |
| Reconcile | Resolve contradictions between two accounts | compare (does not demand resolution) |
Paired operators chain two steps. "Steelman the case for doing nothing. Then identify the weakest point." Or "Diagnose the root cause, assuming the obvious answer is ruled out. Then trace the failure to its origin." Generate exhaustively, then filter with structure.
Constraint markers
The sinc-LLM framework measured constraints as the single highest-importance component, roughly 43% weight, above persona, context, or task. Constraints compress the output space by ruling out directions. High work per token.
Prefer noun-based constraints over adjectives. Adjectives are interpreted relative to the model baseline. Nouns are unambiguous.
| Noun-based | Adjective-based (relative) |
|---|---|
| "Without the words leverage, synergy" | "Keep it simple" (whose version of simple?) |
| "Never start a sentence with..." | "Do not be too formal" |
| "Maximum 80 words" or "Exactly 3 bullets" | "Make it brief" (how brief?) |
| "Focus solely on data-loss risks, not style" | "Avoid being too technical" |
| "Return only a JSON array" | "Improve this" (improve how?) |
The five-constraint ceiling. Constraints listed after the 5th item show measurable attention decay. Accuracy dropped 12 points (78% to 66%) when a 7th was added. The model does not refuse; it quietly stops complying. Max 5 constraints per prompt. Harden that ceiling. Split the prompt if you need more.
The negative constraint. Model training defaults optimize for comprehensiveness, politeness, and safety. If you need something different, the not [default] pattern tells the model what to sacrifice:
The goal is to get a reply, not to explain everything.
"Return the top 3, not an exhaustive list" "Be blunt, not diplomatic" "Quote exact language, not paraphrases"
Without the not clause, the model resolves tradeoffs against its training default. It lands on comprehensive, polite, easy.
Domain anchors
A single domain term pulls the model into an entire expert register: vocabulary, reasoning patterns, formatting conventions. No paragraph of context needed. The ZIP paper confirms nouns carry the most signal in any prompt.
| Term | Register it activates |
|---|---|
| fiduciary | Legal/financial. Duty, risk qualification, precedent. |
| latency | Systems. Measurement, bottlenecks, quantified tradeoffs. |
| idempotent | Systems design. Side-effect awareness, retry safety. |
| monotonic | Math. Formal guarantees, bounds. |
| proximal cause | Causal reasoning. Chain-of-causation. |
| amortization | Financial schedule. Time-value, allocation. |
| thermal runaway | Engineering safety. Cascade failure, compounding effects. |
Use 1 or 2 per prompt. More than that produces jargon without substance.
Context framing
Four framing elements that each carry the weight of paragraphs. They change what a good answer looks like. Without them the model invents its own assumptions:
The audience is CFOs at mid-market SaaS companies skeptical of AI hype.
The goal is to get them to try again, not to explain how AI works.
This is a legal notice. Any ambiguity creates liability. Precision over readability.
This will appear in a LinkedIn post. Mobile-first, no images.
The audience, goal (with its not clause), and stakes lines do more than two paragraphs of context.
The SCOPE framework
For production prompts you reuse, run these five before writing:
- Signal. What processing mode? (audit, critique, extract, derive)
- Constrain. Format plus length plus boundaries.
- Orient. Domain anchor for expert register.
- Persona. Who is the model? Who is the audience?
- Exclude. What to avoid explicitly.
Covering just Signal, Constrain, and Exclude puts you in the top 20% of prompts. All five is top 5% (sinc-LLM framework methodology).
Typically: embed Orient and Persona in the system prompt (they are stable). Apply Signal, Constrain, and Exclude per query.
Structure and ordering
Instruction last. The Instruction Placement Effect puts the task instruction at the end of the prompt. That improves accuracy by roughly 5.6% (recency bias). Order: context, data, constraints, format, then task.
Semantic density. Ultra-dense prompts (SDE over 0.80, every token carrying signal) outperform diluted ones by roughly 8.4 points with zero extra tokens. Cut polite preambles ("can you please"), modal softeners ("maybe", "sort of"), meta-commentary ("I want you to tell me about"), restated context. Replace "briefly" with "in 80 words".
Task before format. Specifying the container before the task lets the container shape the reasoning. Task first, then format.
The failure-mode probe
Append "Where is this analysis most likely to be wrong?" to any analytical prompt. The model surfaces its own assumptions and edge cases. That answer can be worth more than the analysis itself.
Two-pass for accuracy
When accuracy matters more than token cost (contracts, compliance, medical):
- Pass 1. Extract or generate.
- Pass 2. A separate prompt reviews Pass 1 against the source, flagging unsupported claims.
Two-pass can cut hallucination by roughly 31% at 2x token cost. Worth using when a hallucinated answer costs more than the extra tokens.
What to avoid (the noise)
| Word | Why it is noise |
|---|---|
| "thorough" or "comprehensive" | No definition. The model fills in its own version. |
| "good" | Zero information. Good how? Fast? Accurate? Concise? |
| "help me with" | Activates tutor mode, kills task specificity |
| "discuss" or "talk about" | Weakest possible triggers. Shallow descriptive output. |
| "maybe" or "could you" | Modal softeners that increase model uncertainty |
| "this is critical" | Urgency language degrades accuracy. Longer, vaguer, less committed output. |
| "you are an expert" | Every role is expert. No signal. Be specific about the actual role. |
Other traps:
- Synonym piles. "cancellation, termination, expiration, non-renewal" in a cluster adds nothing over a single precise term (+0.8%, noise level per the ZIP paper).
- Adjective constraints. "avoid being too long" barely moves output. Noun constraints move it much more.
- Format before task. The container wins. Keep task first, then format.
- Persona for Claude vs GPT differ. "you are an expert" helped GPT-4o (+6%) but hurt Claude (-3%). Test personas per model.
Model quirks
- Reasoning models (DeepSeek, o-series). Behavioral triggers like "step-by-step" are largely redundant. They already reason internally. Still useful: domain anchors and constraint markers.
- Claude. Over-explains unless boundaries are explicit. Stating goal and tone explicitly does more work.
- GPT-4o. Responds best to numeric constraints ("3 bullets", "under 50 words") and format hints ("in JSON").
Agent-system vocabulary
If you are building agents, these terms define the state machine. A single word becomes a behavioral contract in system prompts:
- Handoff. Package all context into a self-contained prompt, pass to next agent or turn.
- Plan. Emit an ordered sequence first. Plan is data, executed separately.
- Escalate. Recognize out-of-scope, package and hand to human or supervisor.
- Verify. Check against ground truth. Certify or flag. Do not fix.
- Gate. Stop before an irreversible action. Await explicit approval.
- Yield. Stop and pass control back to the orchestrator.
- Backtrack. Unwind to last known good state. Try a different branch.
Architecture patterns to know: ReAct (Thought-Action-Observation loop, the default scaffold), compaction (summarize context near the token limit), sub-agents (bounded workers with clean context windows returning condensed summaries), and planner-executor (separate strategic reasoning from tactical execution).
Further reading
- Anthropic, Effective Context Engineering
- The Prompt Report, arXiv 2406.06608
- Which Words Matter Most in Zero-Shot Prompts, arXiv 2502.03418
- sinc-LLM token optimization guide
- Prompt Engineering Guide, AI Workflows vs Agents
The models are capable enough. The limiting factor in output quality is almost always the specification, not the generation.