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 mentions that user_id is 'admin only', which adds some permission context, but doesn't describe what 'visualization data' entails (e.g., format, structure, whether it's static or dynamic), potential side effects, rate limits, or error conditions. For a data generation tool with zero annotation coverage, this leaves significant gaps in understanding its behavior.

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 a clear main sentence followed by brief Arg/Return sections. It avoids unnecessary elaboration, though the structure could be more integrated (e.g., merging the Arg note into the main description). Every sentence adds value, but the separation into bullet-like sections feels slightly fragmented.

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 (generating visualization data), no annotations, and an output schema present (which likely covers return values), the description is minimally adequate. It explains the purpose and adds some parameter context, but lacks details on behavior, usage scenarios, and how it differs from siblings. With output schema handling returns, the description meets a baseline but has clear gaps in guidance and transparency.

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?

The description adds minimal parameter semantics: it notes that user_id is 'Optional user ID (admin only)', which provides permission context not in the schema (which has 0% description coverage). However, with only one parameter and the schema lacking descriptions, the description doesn't fully explain what 'range' means or how the visualization is generated. It partially compensates but leaves key aspects undocumented.

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 'Generate visualization data for the range' which provides a clear verb ('Generate') and resource ('visualization data for the range'), but it's somewhat vague about what 'the range' specifically refers to in this context. It doesn't distinguish this tool from potential visualization-related siblings like 'get_network_topology' or 'export_metrics', which might provide similar data outputs.

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, which hints at permission requirements, but doesn't explain when to use this tool versus alternatives like 'get_network_topology' or 'export_metrics' that might provide related data. No explicit when/when-not scenarios or prerequisite context is provided.

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