AWS FinOps 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 burden of behavioral disclosure. It mentions that the tool 'finds' target groups, implying a read-only operation, but lacks details on permissions required, rate limits, whether it performs destructive actions, or how it interacts with AWS services. The description is minimal and does not compensate for the absence of annotations.

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 description is well-structured with a clear purpose statement followed by parameter explanations and return information. It is appropriately sized, with no redundant sentences, though it could be slightly more concise by integrating the purpose with the parameter list more seamlessly.

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 the tool's complexity (8 parameters, no annotations, but with an output schema), the description is reasonably complete. It explains the purpose, parameters, and return value, though it lacks behavioral context like error handling or performance considerations. The output schema reduces the need to detail return values, but more guidance on usage and behavior would enhance completeness.

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?

The description includes an 'Args' section that clearly explains each parameter's purpose, such as 'region_name: AWS region name' and 'period: Lookback period in days (default: 7).' This adds significant meaning beyond the input schema, which has 0% description coverage, fully compensating for the schema's lack of parameter details.

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 tool's purpose: 'Find target groups with high error rates (5XX errors).' It specifies the verb ('find'), resource ('target groups'), and scope ('with high error rates'), distinguishing it from sibling tools like 'find_target_groups_with_high_response_time' by focusing on error rates rather than response times.

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. It does not mention sibling tools, prerequisites, or specific contexts for application, leaving the agent without usage direction beyond the basic purpose.

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