# Tool/Agent Registry

> Maintain a single queryable catalog of tools and agents with capability metadata (cost, latency, quality) so the coordinator picks the right one per task.

- **Category**: Agentic AI
- **Subcategory**: Tool Use & Environment
- **Canonical URL**: https://designpattern.fyi/patterns/tool_agent_registry/

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## Description
**Intent**: Let the coordinator agent select among many tools and specialists by measured attributes, not hardcoded choices.

**Context**: Your coordinator agent picks between three speech-to-text services with different price/accuracy tradeoffs, two summarizer agents with different domain strengths, and several search tools with overlapping coverage. They evolve independently and some come from third parties.

**Solution**: A registry exposes a queryable catalog of (1) **tools** — typed inputs/outputs, cost, latency, allowed contexts — and (2) **agents** — capability descriptions, supported tasks, model and provider, price. The coordinator queries the registry per task, ranks candidates by suitability, and dispatches. Registry entries are lightweight metadata, not full schemas.


## Use Cases
- Many tools and/or agents are available and selection is non-trivial.
- A central catalog (internal or marketplace) can be maintained.
- Selection metadata (cost, quality, context window) actually changes which one to pick.





## Trade-offs


### Advantages

- One place to discover all capabilities — tools and agents both.

- Ranking by cost, performance, and context window saves time and money.

- The right pick per task, not the same hardcoded set every time.

- Lightweight metadata scales to many entries without bloating the catalog.




### Considerations & Drawbacks

- Registry becomes a centralization risk — single point of failure and potential vendor lock-in.

- Maintaining accurate metadata requires ongoing effort.

- Registry entries may misrepresent capability; selection must validate in practice.







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