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 full burden. It mentions the tool 'gets' recommendations (implying read-only), but doesn't disclose behavioral traits like authentication requirements (the parameters suggest AWS credentials but no explanation), rate limits, whether it makes API calls, or what kind of recommendations are provided. The description is minimal beyond stating the basic operation.

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 clear sections (Args, Returns) and uses bullet points for parameters. It's appropriately sized for a 6-parameter tool, though the parameter explanations are very brief. Every sentence earns its place, but could be more front-loaded with key usage context.

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 6 parameters with 0% schema coverage and no annotations, the description partially compensates by listing parameters and stating the return type. However, it lacks crucial context for a cost optimization tool: what specific recommendations it provides, how they're generated, or prerequisites. The output schema exists (implied by 'Returns'), so describing return values isn't needed, but other gaps remain.

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 0%, so the description must compensate. It lists all 6 parameters with brief explanations (e.g., 'AWS region to filter recommendations'), adding meaning beyond the schema's bare titles. However, it doesn't explain parameter interactions, defaults, or provide examples (e.g., how credentials are prioritized), leaving gaps.

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: 'Get Lambda function cost optimization recommendations.' It specifies the resource (Lambda functions) and the action (get cost optimization recommendations). However, it doesn't explicitly differentiate from sibling tools like 'get_cost_optimization_ec2' or 'get_all_cost_optimization_recommendations', which would require a 5.

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. With many sibling tools focused on cost optimization for different AWS services (EC2, RDS, EBS, etc.), there's no indication of when Lambda-specific recommendations are needed versus broader tools like 'get_all_cost_optimization_recommendations'.

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