AWS MCP Server

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

No annotations are provided, yet the description carries no behavioral context. It does not indicate this is a safe read-only operation, whether results are paginated, what fields are returned, or required IAM permissions.

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 brief single sentence with no filler. However, given the lack of annotations and output schema, this brevity undermines completeness rather than demonstrating efficient communication.

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?

With no output schema, no annotations, and AWS-specific complexity, the description should compensate by explaining return structure or permissions. It provides neither, leaving significant gaps.

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 description coverage is 100% (profile, region, max_results are fully documented). The description adds no parameter-specific context beyond the schema, warranting the baseline score of 3.

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?

States a clear verb ('List') and resource ('Step Functions state machines'), matching the AWS service terminology. However, it fails to differentiate from sibling tools like 'aws_sfn_describe_state_machine' (which requires an identifier) or 'aws_sfn_list_executions'.

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?

Provides no guidance on when to use this versus 'describe_state_machine' or other siblings. Does not mention that all parameters are optional or typical discovery workflows.

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