Ludus FastMCP

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 'admin only' for the user_id parameter, which is useful behavioral context about permissions. However, it doesn't describe what 'cost estimation' includes, whether this is a read-only operation, what format the estimation returns, or any rate limits or constraints. The description provides minimal behavioral disclosure for a tool with no annotation support.

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 appropriately concise with three brief sentences that cover purpose, parameters, and returns. It's front-loaded with the main purpose statement. While efficient, the structure with 'Args:' and 'Returns:' sections is clear and well-organized for a short description.

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?

The tool has an output schema (which reduces the need to describe return values in the description), but with no annotations and 0% schema description coverage, the description should do more to explain what 'cost estimation' means in this context. It mentions 'admin only' constraints but doesn't provide enough context about what resources are being estimated or how the estimation is calculated. For a cost estimation tool in a complex range management system, this is minimally adequate.

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 schema provides no parameter documentation. The description adds some value by explaining that user_id is 'Optional user ID (admin only)', which provides permission context. However, it doesn't explain what 'the range' refers to or what other implicit parameters might be needed. With 0% schema coverage and only 1 parameter, the description provides basic but incomplete parameter semantics.

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 states 'Get cost estimation for the range' which provides a clear verb ('Get') and resource ('cost estimation'), but it's vague about what 'the range' refers to and doesn't distinguish this tool from any siblings. The purpose is understandable but lacks specificity about what kind of cost estimation is being retrieved.

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 minimal guidance - it mentions 'admin only' for the user_id parameter, but offers no explicit guidance on when to use this tool versus alternatives. With many sibling tools related to ranges, there's no indication of when cost estimation is needed versus other range operations like get_range, get_range_metrics, or get_deployment_metrics.

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