Katzilla MCP

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

Annotations already cover read-only, non-destructive, idempotent, and open-world hints. The description adds valuable behavioral context beyond annotations: it specifies the source (country.is), update frequency (daily), and details about the output envelope (quality scores for freshness/uptime/confidence, citation with source URL, license, and SHA-256 hash). This enhances the agent's understanding of data reliability and auditability.

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 efficiently structured in two sentences: the first states the purpose and source, and the second details the output format and quality metrics. Every sentence adds essential information without redundancy, making it front-loaded and easy to parse.

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 optional parameter), rich annotations (covering safety and idempotency), and the presence of an output schema (implied by the description of the Katzilla envelope), the description is complete. It adequately explains the tool's function, source, update frequency, and output structure, providing all necessary context for an agent to use it effectively.

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 100%, with the schema fully documenting the single parameter 'ip' (type, optionality, and description). The description does not add any parameter-specific semantics beyond what the schema provides, such as format examples or constraints, so it meets the baseline for high schema coverage.

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: 'Get the country for an IP address using country.is.' It specifies the verb ('Get'), resource ('country'), and scope ('IP address'), and distinguishes itself from siblings like geo__ipinfo or geo__geojs by naming the specific source (country.is) and output format (Katzilla envelope).

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: it mentions the source (country.is), update frequency (daily), and output structure. However, it does not explicitly state when to use this tool versus alternatives (e.g., geo__ipinfo for more detailed IP info) or any exclusions, leaving some room for improvement in sibling differentiation.

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