Katzilla MCP

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

Annotations already provide readOnlyHint=true, destructiveHint=false, idempotentHint=true, and openWorldHint=true. The description adds valuable behavioral context beyond annotations: it discloses the source (Shields.io, CC0), update frequency (monthly), and the specific return structure (Katzilla envelope with data, quality, citation components including freshness/uptime/confidence scores and audit hash). This enriches the agent's understanding of the tool's behavior and output characteristics.

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 highly concise and front-loaded: the first sentence states the core purpose, followed by essential behavioral details (source, updates, return format). Every sentence adds critical information (output structure, quality metrics, citation details) with zero waste. It efficiently communicates necessary context in a compact form.

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, annotations, output schema), the description is complete. It covers purpose, source, update cadence, and detailed return structure. With annotations covering safety/idempotency and an output schema presumably detailing the Katzilla envelope, the description fills gaps by explaining the envelope's components (quality scores, citation details), making it fully adequate for agent 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?

Schema description coverage is 100%, with all three parameters (label, message, color) well-documented in the schema. The description does not add any parameter-specific semantics beyond what the schema provides (e.g., no examples, constraints, or usage tips). Baseline score of 3 is appropriate since the schema fully covers parameter documentation.

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: 'Generate a Shields.io badge in JSON format.' It specifies the exact resource (Shields.io badge) and output format (JSON), and distinguishes from siblings by being the only badge-generation tool in the international category. The mention of 'International Data Agent' and source attribution adds specificity.

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 generating badges with the Katzilla envelope format, but does not explicitly state when to use this tool versus alternatives. No sibling tools are directly comparable (e.g., other badge generators), so there's no explicit guidance on alternatives or exclusions. Usage context is implied through the output format and source details.

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