Ludus FastMCP

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 'user_id' is 'admin only,' which hints at permission requirements, but fails to cover critical aspects like whether this is a read-only or destructive operation, potential side effects (e.g., impact on running VMs), rate limits, or error handling. The description is too vague for a configuration tool with potential system-wide effects.

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 and front-loaded with the purpose, followed by parameter and return sections. It uses bullet-like formatting for clarity and avoids unnecessary verbosity. Every sentence adds value, such as the parameter explanations, making it efficient and easy to scan.

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 complexity of auto-scaling configuration, the description is moderately complete. It covers parameters and mentions a return value, but lacks details on behavioral traits, usage context, and output specifics (though an output schema exists, reducing the need for return value explanation). With no annotations and 0% schema coverage, it should provide more guidance on system impact and prerequisites to be fully 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%, but the description compensates by listing all five parameters with brief explanations (e.g., 'Enable or disable auto-scaling' for 'enable'). It adds meaning beyond the schema by clarifying that 'user_id' is 'Optional user ID (admin only),' providing context not evident from the schema alone. However, 'scaling_policy' is only described as 'Scaling policy configuration,' which remains vague.

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: 'Configure auto-scaling for the range.' It specifies the verb ('configure') and resource ('auto-scaling for the range'), making the intent explicit. However, it does not differentiate from sibling tools, as no other auto-scaling tools are listed among siblings, but the purpose is still clear and specific.

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 lacks context such as prerequisites, when it should be applied (e.g., during deployment or maintenance), or any exclusions. Without such information, users must infer usage from the purpose alone, which is insufficient for effective tool selection.

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