Katzilla MCP

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, and openWorldHint=true, covering safety and idempotency. The description adds valuable behavioral context beyond annotations: it discloses the source (7Timer Free API), update frequency (monthly), and the return structure (Katzilla envelope with data, quality, citation details including SHA-256 hash). This enriches 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 source details and return structure. Every sentence adds value: the first defines the tool, the second provides source context, and the third explains the output format. There is no wasted text, making it highly efficient and well-structured.

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 (3 parameters, 100% schema coverage, annotations, and an output schema), the description is complete. It covers purpose, source, update frequency, and return structure, which, combined with structured fields, provides sufficient context for an agent to use the tool effectively without needing additional explanation of parameters or outputs.

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 clear descriptions for lat, lon, and product (including enum values). The description does not add any parameter-specific semantics beyond what the schema provides, such as explaining the implications of product choices (e.g., astro vs. civil). Given the high schema coverage, the baseline score of 3 is appropriate, as the description doesn't compensate but also doesn't 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 explicitly states the tool's purpose with a specific verb ('Get weather forecasts') and resource ('from 7Timer for a given location'), clearly distinguishing it from sibling tools that focus on agriculture, consumer data, crime, crypto, etc. It also specifies the data source (7Timer Free API) and update frequency (monthly), making the purpose highly specific and differentiated.

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 implies usage for weather forecasting needs, but does not explicitly state when to use this tool versus alternatives (e.g., other weather-related tools like environment__canada-weather or environment__openmeteo-aq). It provides context about the source and update frequency, but lacks explicit guidance on when-not-to-use or named alternatives, leaving usage somewhat implied rather than clearly defined.

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