List all AWS regions enabled on your account by bootstrapping an EC2 client with a chosen region, defaulting to us-east-1.
List all AWS regions enabled on the account. bootstrap_region is only used to construct the EC2 client (the call itself is global). Defaults to us-east-1.
| Name | Required | Description | Default |
|---|---|---|---|
| bootstrap_region | No | Region used to bootstrap the EC2 client (default: us-east-1). | us-east-1 |
Changes observed during successful MCP inspections.
v2.24.0v2.23.8v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations provided, but description discloses that the call is global and the region parameter is just for client construction. Adequate behavioral transparency for a read-only list.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two sentences, front-loaded with purpose, no wasted words. Highly concise.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given no output schema and simple single-parameter tool, description fully covers what the tool does and how the parameter behaves.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema already describes the parameter, but description adds that the call itself is global, clarifying that the region doesn't scope results. Adds value beyond schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
Clearly states it lists all AWS regions enabled on the account; specific verb and resource. No sibling tool duplicates this functionality.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
Explains that bootstrap_region is only used to construct the EC2 client and the call is global, giving clear context. No need for when-not-to-use as it's a simple listing.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.