AWS MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure but fails to mention critical AWS list operation behaviors: pagination handling (despite the 'limit' parameter), whether a NextToken is returned (not shown in schema), read-only safety, or the structure of returned group objects.

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 single 6-word sentence is efficiently structured and front-loaded with the core action. However, given the lack of annotations and output schema, the extreme brevity leaves significant gaps in necessary context, making it under-informative rather than appropriately concise.

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 zero annotations, no output schema, and the complexity of AWS Cognito operations (including pagination implications), the 6-word description is insufficient. It lacks mention of pagination tokens, return value structure, authentication requirements, and typical use cases for group management.

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?

Schema description coverage is 100%, with all 4 parameters (profile, region, user_pool_id, limit) fully documented in the schema. The description adds no additional semantic information beyond what the schema already provides, warranting the baseline score of 3 per the rubric.

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 verb (List) and resource (groups in a Cognito user pool), distinguishing it from sibling tools like aws_cognito_list_user_pools (which lists pools, not groups within them). However, it does not explicitly differentiate from aws_cognito_list_users, which could cause confusion between user groups and individual users.

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?

There is no guidance on when to use this tool versus alternatives, nor any mention of prerequisites like obtaining the user_pool_id from aws_cognito_list_user_pools first. The description provides purely functional information without operational context.

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