AWS MCP Server

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

No annotations are provided, and the description fails to disclose read-only nature, AWS API rate limits, pagination behavior, or required IAM permissions (ecr:DescribeRepositories). The agent must infer safety from the 'describe' verb alone.

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 at only four words with no redundancy. However, the brevity leaves significant gaps in necessary context—every word earns its place, but more words were needed for completeness.

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 an AWS API tool with 4 parameters and no output schema, the description is inadequate. It omits what repository attributes are returned, how pagination works with max_results, and does not reference the AWS profile/region context established by other tools in the suite.

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?

Input schema has 100% description coverage (profile, region, repository_names, max_results), so the schema carries the burden. The description adds no parameter syntax, formatting details, or behavior of optional filters (e.g., that empty repository_names returns all repositories). Baseline 3 warranted.

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 resource (ECR repositories) and actions (list and describe) clearly, but lacks specificity about what 'describe' entails (e.g., repository URIs, policies, scan status) and does not distinguish from sibling tools like aws_ecr_describe_images or aws_ecr_list_images.

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 alternatives (e.g., aws_ecr_list_images for image listings) or when to filter by repository_names versus retrieving all repositories. No prerequisites or permissions mentioned.

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