AWS MCP Server

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

With no annotations, description carries full burden. It helpfully notes 'single' metric constraint (distinguishing from batch APIs), but omits other critical behaviors: read-only nature, up to 1,440 data point limit, that periods must be multiples of 60 for detailed metrics, and CloudWatch API costs.

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 12-word sentence front-loaded with action and scope. Every word earns its place; no redundancy.

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?

Despite 9 parameters and no output schema/annotations, the minimal description covers basic purpose. However, it lacks output format details, pagination behavior, or error conditions expected for a complex AWS API operation.

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 has 100% description coverage with clear examples (e.g., 'CPUUtilization', 'AWS/EC2'). Description adds no semantic clarifications beyond what schema provides, earning baseline 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?

Clear verb 'Get' and resource 'CloudWatch metric', with explicit mention of supported statistics (Average, Sum, Min, Max) and time range. However, it does not distinguish from sibling tool 'aws_cloudwatch_get_metric_data' which serves a similar purpose.

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?

No guidance provided on when to use this tool versus 'get_metric_data' (which supports batching multiple metrics) or 'list_metrics' (for discovery). No prerequisites mentioned (e.g., knowing namespace/dimensions first).

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