EBS CloudWatch Metrics MCP

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions that the tool returns snapshot details (ID, size, status, creation time), which is helpful, but lacks critical behavioral information such as whether it's a read-only operation, potential rate limits, authentication requirements, or pagination behavior. For a tool with no annotations, this is a significant gap.

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 appropriately sized and front-loaded: it starts with the core purpose, followed by return details, and then parameter explanations in a structured 'Args' section. Every sentence adds value without redundancy, making it efficient and easy to parse.

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 that there's an output schema (which covers return values), no annotations, and 3 parameters with 0% schema coverage, the description does a decent job. It explains the purpose, return details, and parameters, but lacks behavioral context (e.g., safety, limits) and usage guidelines. It's adequate but has clear gaps, making it a minimum viable description.

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 description includes an 'Args' section that explains each parameter: 'volume_id' is described with an example, 'max_results' specifies a default value, and 'region' is noted as optional. Since schema description coverage is 0%, this adds substantial meaning beyond the bare schema, compensating well for the lack of schema descriptions. It doesn't reach 5 because it could provide more context, such as valid region formats or constraints on 'max_results'.

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 clearly states the tool's purpose: 'EBS 볼륨의 모든 스냅샷 목록을 조회합니다' (retrieves all snapshots of an EBS volume). It specifies the verb (조회/retrieve) and resource (EBS 볼륨 스냅샷/EBS volume snapshots), but doesn't explicitly differentiate from sibling tools like 'get_snapshot_size' or 'list_ebs_metrics', which is why it doesn't reach a score of 5.

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 description provides no guidance on when to use this tool versus alternatives. It doesn't mention sibling tools or contexts where other tools might be more appropriate, such as using 'get_snapshot_size' for specific size details or 'list_ebs_metrics' for metrics. This leaves the agent without clear usage instructions.

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