# Communicative Dehallucination

> When an agent would have to invent missing context to comply with an instruction, flip the direction — have it ask the instructor for the missing detail before answering.

- **Category**: Agentic AI
- **Subcategory**: Multi-Agent
- **Canonical URL**: https://designpattern.fyi/patterns/communicative_dehallucination/

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## Description
**Intent**: When an instructed agent would have to invent missing context to comply, have it reverse roles and ask the instructor for the missing detail before answering.
**Context**: Two agents are communicating in an instructor-and-assistant shape — an orchestrator telling a coding sub-agent what to do, a planner handing work to an executor. The instruction arrives with a decisive detail missing: a specific class name, an API version, an ambiguous unit of measure, or which of several plausible interpretations the instructor actually meant.
**Solution**: Define an explicit role-reversal protocol: when the assistant detects that the instruction is missing a deciding piece of context, it pivots and emits a focused question back to the instructor. The instructor answers, and only then does the assistant produce its output. Bound the depth (one or two reversals) to prevent infinite back-and-forth.



## Use Cases
- Multi-agent setups where the assistant would otherwise fabricate missing context to comply with instructions.
- A reverse-direction question channel between agents can be implemented cleanly.
- Fabrications would propagate downstream and be hard to detect at the artifact boundary.






## Trade-offs


### Advantages

- Targets the specific hallucination point before it happens, not after.

- Cheaper than full multi-agent debate — the question is tightly scoped.

- Produces a more faithful artifact at the next hand-off.




### Considerations & Drawbacks

- Adds latency for every clarification round.

- Detecting the gap is itself a model judgment that can fail.

- Risk of infinite ping-pong without a strict depth bound.







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**Reference**: [Original Source](https://www.agentpatternscatalog.org/patterns/communicative-dehallucination/)