# The agent discovery glossary

> Plain-English definitions of crawling, retrieval, citations, MCP, OpenAPI, GEO, and useful completion.

Canonical: https://byagents.dev/humans/agent-discovery-glossary
Published: 2026-09-13
Reviewed: 2026-09-13
Publisher: ByAgents
Type: Reference
Level: Business
Outcome: Translate common agent-distribution terms into practical business meaning.

Agent discovery combines familiar web concepts with newer tool interfaces. These definitions separate the layers so a technical recommendation can be evaluated on what it actually changes.

## Agent and assistant
An **assistant** is a broad product or interface description. An **agent** can choose and execute steps using available tools toward a task. A product may expose different capabilities in different modes. An assistant name alone does not establish search access, authorization, or autonomy.

## Crawling, indexing, and retrieval
**Crawling** means fetching resources for processing. **Indexing** means organizing content so it can be found later. **Retrieval** means selecting information for a particular query or task. A successful crawl does not prove inclusion in an index, and indexing does not guarantee retrieval.

## SEO and GEO
**Search engine optimization (SEO)** is work to improve search discoverability and performance. **Generative engine optimization (GEO)** is an industry term commonly used for improving representation in generative answers. It is not one standardized technical specification. Define the outcome being measured instead of relying on the acronym.

## Structured data and JSON-LD
**Structured data** gives explicit fields and relationships to information. **Schema.org** is a vocabulary often used on websites. **JSON-LD** is a format for linked data. These can describe entities and facts; they do not make an unsupported claim true.

## Canonical URL
A **canonical URL** identifies the preferred version of a page among duplicate or similar representations. Keeping HTML, Markdown, feeds, and references connected to a stable identity helps readers understand which document they are using. Search engines treat canonical signals according to their own systems.

## Citation and provenance
A **citation** points to a source for a claim. **Provenance** describes where information came from and how it was produced. A useful evidence record distinguishes a first-party assertion, independent source, example, and measured test result.

## MCP and OpenAPI
**MCP** is a protocol for compatible AI applications to connect to servers exposing tools and context. **OpenAPI** is a specification for describing HTTP APIs. They serve different interfaces and can coexist. Neither guarantees that a particular agent will discover or adopt a product.

## Tool registry and connected tool
A **registry** catalogs metadata. A **connected tool** is available in a specific runtime after configuration and permission. Publication, connection, and invocation are separate events. See the MCP guide for the implications of this distinction.

## llms.txt
**llms.txt** is a proposed Markdown index convention for language-model readers. It can point to focused documentation. It is not robots.txt, an authentication mechanism, or a universal ranking requirement.

## Handoff and activation
A **handoff** transfers the customer’s task to a next step, such as checkout, booking, or an API operation. **Activation** is a defined first useful customer result. A job accepted, form submitted, or item added to a cart may be an intermediate event rather than completion.

## Controlled test and organic discovery
A **controlled test** is a run initiated for evaluation. **Organic discovery** means an independent user or agent encounters the product without the operator introducing it as part of that test. Keep introduced, branded, unbranded, and unknown routes labeled separately.

## Related reading

- [What is an AI agent?](https://byagents.dev/humans/what-is-an-ai-agent)
- [SEO, GEO, and agent discovery: what actually changes?](https://byagents.dev/humans/seo-geo-and-agent-discovery)
- [MCP, registries, and getting your tools discovered](https://byagents.dev/humans/mcp-and-tool-discovery)