MCP Server Cards (SEP-2127) vs Agentic Resource Discovery
They sit at the same step and overlap in purpose; the fields above are the basis for choosing.
| MCP Server Cards (SEP-2127) Server Card | Agentic Resource Discovery ARD | |
|---|---|---|
| Lifecycle step | 1 Discover: What is here, and where? | 1 Discover: What is here, and where? |
| Answers | How can a client learn what an MCP server offers before connecting to it? | Where are an organization's discoverable agentic resources (MCP servers, A2A agents, skills, registries), and how can they be found by search rather than pre-installed one at a time? |
| Governed by | Model Context Protocol project (SEP process, MCP governance) | Authored by individuals at Google, Microsoft and Hugging Face (Junjie Bu, R.V. Guha, Shaun Smith); published as an open GitHub project (ards-project/ard-spec) with no formal standards body yet; contributions acknowledged from AWS, Cisco, Databricks, GitHub, GoDaddy, Nvidia, Salesforce and Snowflake |
| Status (issuer's words) | SEP-2127 Final (2026-10-06); the MCP Registry working group page still describes Server Cards as experimental | Proposal |
| Phase | candidate | draft |
| Version | SEP-2127 (Final) (2026-10-06) | v0.91 (2026-08-26) |
| Form / transport | document format | well-known file |
| Found at | Static JSON Server Card fetched before connecting; location defined in SEP-2127 | /.well-known/ard.json |
| Adoption | unmeasured | observed — agenticresources.dev own probe, 2026-09-04 |
| Evidence | 2 verified, 1 reported | 2 verified, 2 reported |
| Primary use case | Let agents discover my API or service | Let agents discover my API or service |
| Last verified | 2026-10-19 (current) | 2026-10-19 (current) |
| Specification | https://github.com/modelcontextprotocol/modelcontextprotocol/blob/main/seps/2127-mcp-server-cards.md | https://raw.githubusercontent.com/ards-project/ard-spec/main/spec/ard.md |
When to use which
- Choose MCP Server Cards (SEP-2127) when your question is “How can a client learn what an MCP server offers before connecting to it?” and you accept its maturity: phase candidate, adoption unmeasured.
- Choose Agentic Resource Discovery when your question is “Where are an organization's discoverable agentic resources (MCP servers, A2A agents, skills, registries), and how can they be found by search rather than pre-installed one at a time?” and you accept its maturity: phase draft, adoption observed (agenticresources.dev own probe, 2026-09-04).
Read the full articles
- MCP Server Cards (SEP-2127): How can a client learn what an MCP server offers before connecting to it?
- Agentic Resource Discovery: Where are an organization's discoverable agentic resources (MCP servers, A2A agents, skills, registries), and how can they be found by search rather than pre-installed one at a time?