AWS MCP Server

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

No annotations are provided, so the description carries the full disclosure burden. While it notes 'recent' (implying time-bounded results), it fails to define the time window, describe pagination behavior with `max_items`, confirm the read-only nature, or mention AWS rate limits and credential requirements.

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?

A single, front-loaded sentence efficiently conveys the tool's purpose without redundancy. Every word serves a descriptive function.

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 100% input schema coverage, the description adequately covers inputs. However, with no output schema, no annotations, and no description of return values or pagination behavior, it provides only minimum viable information for an AWS list 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?

With 100% schema description coverage, all four parameters (profile, region, distribution_id, max_items) are fully documented in the schema itself. The description adds no supplementary parameter information, 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?

The description provides a specific verb ('List') and resource ('cache invalidation requests for a CloudFront distribution'), clearly differentiating from sibling tools like `aws_cloudfront_create_invalidation` and `aws_cloudfront_list_distributions`. However, it does not explicitly name siblings or describe the relationship between listing and creating invalidations.

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 like `aws_cloudfront_create_invalidation`, prerequisites such as IAM permissions, or expected workflow (e.g., checking status after creation). It merely states the operation without contextual usage advice.

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