Ludus FastMCP

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 states the tool performs a connectivity test but doesn't describe what the test entails, whether it's destructive, what permissions are needed beyond 'admin only', or how results are returned. The mention of 'admin only' for user_id adds some context about authorization needs, but overall behavioral traits are insufficiently covered for a mutation-like testing tool.

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 sized and well-structured with clear sections for the purpose, arguments, and returns. Each sentence serves a purpose, though the parameter explanations could be more detailed. The front-loaded purpose statement is effective, making it easy to understand the tool's function quickly.

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 (5 parameters, no annotations) and the presence of an output schema (which handles return values), the description is partially complete. It covers the basic purpose and parameters but lacks usage guidelines, detailed behavioral context, and parameter constraints. For a network testing tool with admin implications, more completeness is needed to guide effective use.

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 5 parameters with brief explanations, adding meaning beyond the bare schema. However, the explanations are minimal (e.g., 'Source VM name' for source_vm) and don't clarify constraints like format or relationships between parameters (e.g., port is required for tcp/udp but not icmp). This provides basic but incomplete semantic context.

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: 'Test network connectivity between VMs.' It specifies the verb ('Test'), resource ('network connectivity'), and scope ('between VMs'), making the function unambiguous. However, it doesn't explicitly differentiate from sibling tools like 'diagnose_network_issues' or 'capture_network_traffic', which prevents a perfect score.

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. While it mentions 'admin only' for the optional user_id parameter, this is a parameter detail rather than usage context. There's no mention of prerequisites, scenarios where this tool is appropriate, or how it differs from related tools like 'diagnose_network_issues'.

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