Katzilla MCP

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already provide hints (readOnlyHint: true, destructiveHint: false, idempotentHint: true, openWorldHint: true), covering safety and idempotency. The description adds valuable context beyond this: it discloses the source ('Nationalize (Free Tier)'), update frequency ('updates monthly'), and return format ('Katzilla envelope { data, quality, citation }') with details on quality scoring and citation contents. This enriches behavioral understanding without contradicting annotations.

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 front-loaded with the core purpose in the first sentence, followed by supporting details in a structured manner. Every sentence adds value: the second sentence specifies the source and update frequency, and the third explains the return format and its components. There is no wasted text, making it highly efficient.

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 low complexity (one parameter), rich annotations (covering safety and behavior), and the presence of an output schema (implied by 'Returns the Katzilla envelope'), the description is complete. It covers purpose, source, update frequency, and return structure, providing sufficient context for an agent to use the tool effectively without needing to explain basic parameters or output details.

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 input schema has 100% description coverage, with the 'name' parameter fully documented. The description does not add any additional semantic details about the parameter beyond what the schema provides (e.g., format examples or constraints). Since schema coverage is high, the baseline score of 3 is appropriate, as the description does not compensate but also does not detract.

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: 'Predict the nationality of a person based on their name.' It specifies the verb ('predict'), resource ('nationality'), and scope ('based on their name'), distinguishing it from sibling tools like 'agify' or 'genderize' which predict different attributes. This is specific and unambiguous.

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 usage: 'Source: Nationalize (Free Tier), updates monthly.' This indicates when to use it (for nationality prediction via this specific API) and implies limitations (free tier, monthly updates). However, it does not explicitly state when not to use it or name alternatives among siblings, such as other demographic tools.

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