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, covering safety and idempotency. The description adds valuable context beyond annotations: it specifies the source ('datos.gob.es'), update frequency ('updates daily'), and details about the return format ('Katzilla envelope with quality scores and citation info including SHA-256 hash'). This enhances transparency 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 format specifics. Every sentence adds value: the first defines the action, the second provides source context, and the third explains the output structure. There is no wasted text, making it highly concise 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 complexity (search with parameters), rich annotations (covering safety and idempotency), and the presence of an output schema (implied by 'Returns the Katzilla envelope'), the description is complete. It covers purpose, source, update frequency, and output details, providing sufficient context for an agent to use the tool effectively without needing to explain return values redundantly.

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 documentation for 'query' and 'limit' parameters. The description does not add any additional semantic details about the parameters beyond what the schema provides, such as query syntax examples or limit usage context. With high schema coverage, the 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 specific action ('Search the Spanish government open data portal'), the resource ('public datasets'), and the source ('datos.gob.es'). It distinguishes from siblings by specifying the Spanish government context, unlike other government tools like 'government__data-australia' or 'government__data-canada'.

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 when to use this tool: searching for public datasets from the Spanish government open data portal. It mentions the source and update frequency ('updates daily'), which helps guide usage. However, it does not explicitly state when not to use it or name specific alternatives among siblings, such as other country-specific data portals.

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