Ops 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. It explains what the tool does (aggregates resource usage across job runs) and includes important operational guidance about the 'env' parameter. However, it lacks details on permissions needed, rate limits, error conditions, or whether this is a read-only operation (though implied by 'Get').

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, aggregation details, usage context, parameter explanations, and return information. Every sentence adds value, though the 'IMPORTANT' note about the 'env' parameter could be integrated more smoothly. The text is appropriately sized for a tool with three parameters.

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 moderate complexity (3 parameters, no annotations, but with output schema), the description provides good coverage. It explains the tool's purpose, parameters, and return value ('Returns a cost summary with per-job and total resource usage'). The presence of an output schema means the description doesn't need to detail the return structure, making this reasonably complete.

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 0% schema description coverage, the description fully compensates by providing clear semantic explanations for all three parameters. It explains that 'application_id' is optional and filters to one application, 'days' specifies the lookback period with a default, and 'env' is the target environment with specific valid values and important usage guidance.

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 with specific verbs ('Get a summary', 'Aggregates') and resources ('EMR Serverless resource usage and estimated costs', 'vCPU hours, memory GB-hours, and storage GB-hours across recent job runs'). It distinguishes itself from sibling tools by focusing on cost analysis rather than browsing, listing, or managing resources.

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 clear context for when to use this tool ('Useful for understanding compute costs'), but does not explicitly mention when not to use it or name specific alternatives. The guidance on the 'env' parameter ('IMPORTANT: Do NOT guess or default. Ask the user which environment if not specified') offers operational direction but not tool-selection advice.

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