What is a MCP server?

LLMs are like genies trapped in a bottle: their knowledge is limited by their training data, specifically their knowledge cutoff date, and they can't take actions.

Several frameworks have been proposed to enable models to interact with their environments. Since July, 2023, Bedrock has been offering Agents Action Groups. More recently (Nov, 2024) Anthropic, the creators of Claude AI, have introduced the Model Context Protocol (MCP).

MCP is a specification, backed by a number of open source implementations and a very good documentation, of a protocol that enables agents to gather knowledge through resources, take actions through tools, be given instructions through prompts, while keeping session context. Applications that run LLMs, such as Claude Desktop, act as clients of MCP servers.

Adoption is growing and MCP servers now cover a wide range of tasks, from searching in your local files, to connecting to a database, to placing an order on your favorite store.

What is the AWS Service Reference Information?

AWS Service Reference Information, or Service Authorization Reference, is a repository of all AWS documentation related to IAM Actions, Resources and Condition Keys, gathering information that was otherwise scattered across multiple AWS service documentations.

In 2024, AWS added programmatic support to access this data and, since March 13, 2025, Service Reference Information includes Resources and Condition Keys.

Introducing AWS Service Reference Information MCP Server

Today, I'm glad to introduce the Introducing AWS Service Reference Information MCP Server, an MCP server implementation that specialises in querying Service Reference Information, enabling your LLM to

• have access to the most recent API changes (« hey Claude, what are the condition keys for ? »)
• provide more accurate answers by limiting model hallucinations

Thanks to the AWS Service Reference Information MCP Server, you can quickly find condition keys for any IAM action or resource, or conversely find all actions that use a resource or condition key.

To start using the AWS Service Reference Information MCP Server, visit my GitHub repository or just add the following configuration to your Claude Desktop App.

"mcpServers": {
  "aws-service-authorization-reference": {
    "command": "docker",
    "args": ["run", "-i", "--rm", "psantus86/aws-service-authorization-reference-mcp-server:latest"]
  }
}

Feedback is a gift! Don't hesitate to let me know how you use this MCP server and contribute to the GitHub repo!

(Update: in the next post, I share some insights and example of how the MCP servers improves LLM answers)