AWS MCP Server

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden of behavioral disclosure but only states the basic operation without mentioning safety characteristics (read-only), pagination behavior, rate limits, or error conditions. The verb 'List' implies non-destructive behavior, but explicit confirmation is absent.

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?

The description is a single, efficient sentence that leads with the action verb and avoids redundancy. While appropriately sized for a simple list operation, it is arguably too minimal given the lack of annotations, though this primarily affects completeness rather than conciseness itself.

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 the tool's simplicity (a read-only list operation) and complete input schema documentation, the description covers essential functionality. However, the absence of annotations combined with no disclosure of behavioral traits or output characteristics leaves gaps in operational completeness.

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?

The input schema has 100% description coverage for all three parameters, establishing a baseline of 3. The description mentions the optional filter behavior for topic_arn, but does not add significant semantic depth or usage examples beyond what the schema already provides.

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?

The description uses the specific verb 'List' with resource 'SNS subscriptions' and clarifies scoping with 'optionally filtered by topic ARN'. However, it does not explicitly differentiate from sibling tools like `aws_sns_list_topics`, relying solely on the tool name for distinction.

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?

The phrase 'optionally filtered by topic ARN' implies the filter can be omitted to list all subscriptions, providing basic usage context. However, it lacks explicit guidance on when to use this tool versus sibling SNS tools and omits prerequisites like AWS authentication requirements.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.