# Query-Decomposition Agent

> An agent whose explicit job is to split an incoming user query into smaller independent sub-queries that can be answered sequentially or in parallel, then merge results.

- **Category**: Agentic AI
- **Subcategory**: Planning & Control Flow
- **Canonical URL**: https://designpattern.fyi/patterns/query_decomposition_agent/

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## Description
**Intent**: An agent whose explicit job is to split an incoming user query into smaller independent sub-queries that can be answered sequentially or in parallel, then merge results.
**Context**: A user asks a multi-part question — "compare the privacy implications of these three vendors across GDPR, HIPAA, and SOC 2". Answering it as one prompt produces a sprawling, low-quality response: the model interleaves vendor-axis facts with regulation-axis facts and misses combinations.
**Solution**: - Front the workflow with a decomposer agent whose system prompt asks it to enumerate independent sub-queries that together answer the user's question. - Run each sub-query (in parallel or sequence) through the answering agent, RAG retriever, or tool. - Pass the leaf answers to an aggregator that composes the final response. - The decomposition output is itself an inspectable artefact the user can challenge.


## Use Cases
- Questions are compositional (entity × dimension matrices, multi-source comparisons).
- Sub-queries are usefully independent.
- Latency budget allows parallel leaf execution.





## Trade-offs


### Advantages

- Multi-part questions get scaffolded answers with per-leaf depth.

- Leaf parallelism cuts latency on independent sub-queries.

- Decomposition output is an inspectable artefact users can challenge.




### Considerations & Drawbacks

- Mis-decomposition silently drops dimensions of the question.

- Over-decomposition fans out into too many leaves and balloons cost.

- Aggregation can lose nuance present in individual leaves.







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**Reference**: [Original Source](https://www.agentpatternscatalog.org/patterns/query-decomposition-agent/)