AWS MCP Server

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

No annotations provided, so description carries full burden of behavioral disclosure, yet it provides no information on pagination (Marker/NextToken), rate limiting, required IAM permissions (kms:ListKeys), or whether disabled keys are included. Does not contradict annotations, but fails to disclose essential AWS API behaviors.

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?

Single sentence with no fluff, appropriately front-loaded. However, given the lack of annotations and output schema, the extreme brevity contributes to under-specification rather than 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?

For a simple enumeration tool with a flat input schema and no output schema, the description is minimally adequate but lacks important context given zero annotations. Should disclose pagination behavior and whether this returns all keys or requires filtering.

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 coverage is 100% with clear descriptions for 'profile' and 'region'. The tool description adds no parameter semantics beyond the schema, but meets the baseline for high-coverage schemas.

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 the basic action (List KMS keys) and scope (in the account) with a specific verb, but lacks differentiation from sibling `aws_kms_describe_key` (which retrieves details of a specific key) and `aws_kms_list_aliases`. Does not clarify what attributes of the keys are returned.

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 tool versus siblings like `aws_kms_describe_key` for getting detailed key metadata, or `aws_kms_list_aliases` for viewing friendly names. No mention of pagination behavior or permission requirements.

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