Katzilla MCP

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

Annotations already indicate the tool is read-only, non-destructive, idempotent, and open-world. The description adds valuable behavioral context beyond annotations: it specifies the source ('GNews (GNews Terms)'), update frequency ('updates hourly'), and details the return format ('Katzilla envelope { data, quality, citation }') with explanations of quality scores and citation components. 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 efficiently structured in two sentences: the first states the purpose and source, and the second details the return format and its components. Every sentence adds essential information without redundancy, making it front-loaded and appropriately sized for quick comprehension.

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, rich annotations (readOnlyHint, destructiveHint, idempotentHint, openWorldHint), and the presence of an output schema, the description is complete. It covers purpose, source, update frequency, and return format, compensating for any gaps. With annotations and output schema handling safety and structure, no additional details are necessary for 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?

The input schema has 100% description coverage, with clear defaults and descriptions for all parameters (category, lang, limit). The description does not add significant semantic details beyond the schema, as it only mentions 'by category and language' without elaborating on parameter usage or constraints. Given the high schema coverage, a baseline score of 3 is appropriate.

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 with specific verbs ('Get top news headlines') and resources ('from GNews'), specifying the filtering criteria ('by category and language'). It distinguishes itself from sibling tools by focusing on news headlines from a specific source (GNews), unlike other media tools like 'media__hacker-news' which targets a different platform.

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 ('Get top news headlines by category and language from GNews') and mentions the update frequency ('updates hourly'), which helps determine when to use it. However, it does not explicitly state when not to use this tool or name specific alternatives among siblings, such as when needing different news sources or more detailed articles.

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