AWS MCP Server

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

No annotations provided, yet description discloses almost nothing beyond the operation name. Does not mention read-only nature, pagination behavior (despite max_results parameter), return format, or rate limit considerations. Carries minimal burden despite zero annotation coverage.

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 terse at 5 words/6 tokens. No redundant words, but brevity crosses into under-specification given the tool's complexity (4 parameters, no output schema, many siblings). Structure is front-loaded but insufficient.

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?

Inadequate for a 4-parameter AWS API wrapper with no output schema and no annotations. Description omits what data is returned, how pagination works, and crucially—how this differs from describe_services. Should explain the list-vs-describe distinction typical in AWS APIs.

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, so baseline applies. Description mentions 'in a cluster' which loosely corresponds to the required 'cluster' parameter, but adds no semantic value beyond what the schema already provides (names, types, descriptions).

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 clear verb (List) + resource (ECS services) + scope (in a cluster). However, fails to differentiate from sibling 'aws_ecs_describe_services'—both involve services but the distinction between listing summaries versus describing details is not clarified.

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 tool versus alternatives. Siblings include describe_services (for detailed metadata) and list_clusters (for cluster-level aggregation), but description offers no selection criteria or prerequisites.

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