AWS MCP Server

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

No annotations are provided, so the description carries full disclosure burden. While 'List' implies a read-only operation, the description does not confirm safety (idempotent, non-destructive), mention pagination behavior, or indicate required IAM permissions (ecs:ListClusters).

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?

Extremely concise at 7 words with no filler. The main verb appears first. However, given the absence of annotations and output schema, the brevity leaves significant gaps that could have been addressed with one additional sentence about prerequisites or pagination.

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?

For a simple listing tool with 100% schema coverage and no output schema, the description is minimally sufficient. It could be improved by noting the relationship to 'aws_ecs_describe_clusters' or mentioning that results may be paginated, but it covers the basic operation scope.

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?

Input schema has 100% description coverage with clear parameter descriptions for 'profile' and 'region'. The description text 'in the account/region' loosely maps to these parameters but adds no syntax details, format constraints, 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?

Description clearly states the verb (List) and resource (ECS clusters) with scope (account/region). However, it does not distinguish from sibling 'aws_ecs_describe_clusters' which requires specific cluster identifiers, or differentiate from similar list operations in other services like EKS or EMR.

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?

Description provides no guidance on when to use this tool versus alternatives like 'aws_ecs_describe_clusters', nor does it mention that this operation typically returns cluster ARNs/names that serve as prerequisites for the describe operations.

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