AWS MCP Server

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

Without annotations, the description carries the full burden. It successfully discloses the specific data returned (including security-relevant fields like vulnerability counts), but fails to indicate this is a safe read-only operation, lacks mention of AWS API rate limits, and doesn't describe error cases like missing repositories or images.

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 efficiently front-loaded with verb and resource, followed by a colon-separated list of return fields. Zero redundancy; every word earns its place by conveying specific metadata capabilities.

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 no output schema exists, the description appropriately compensates by listing specific return fields. However, lacking annotations and any mention of AWS credential requirements or pagination behavior (despite max_results parameter), it falls slightly short of complete behavioral context for an AWS API tool.

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, the schema already documents all parameters including the image_ids object structure and profile/region conventions. The description implies these parameters by referencing 'ECR images' but adds no semantic detail beyond the schema's existing documentation.

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 specific action ('Get detailed metadata'), the resource ('ECR images'), and enumerates exact return fields (size, push date, scan status, vulnerability counts). This distinguishes it from sibling 'aws_ecr_list_images' which implies a simpler enumeration without rich metadata.

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 siblings like 'aws_ecr_list_images' or 'aws_ecr_describe_repositories', nor does it mention that image_ids filtering is optional (can describe all images in repository) or required authentication prerequisites.

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