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 context beyond annotations: it specifies the data source URL, update frequency ('updates daily'), license information ('CC0 / Public Domain'), and details about the return format ('Katzilla envelope { data, quality, citation }') with quality metrics and citation components. This enhances understanding of the tool's behavior 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 covers purpose, source, and data scope; the second details return format and metadata. Every sentence adds critical information without redundancy, making it front-loaded and appropriately sized for the tool's complexity.

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 has annotations covering safety and idempotency, a rich output schema (implied by the description of the Katzilla envelope), and 100% schema coverage for inputs, the description is complete. It adds necessary context about the data source, update frequency, license, and return structure, compensating well for any gaps not covered by structured fields.

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 both parameters (query and limit) fully described in the schema. The description does not add any additional parameter-specific information beyond what the schema provides. According to guidelines, when schema coverage is high (>80%), the baseline score is 3 even with no param info in the description.

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: 'Search the Dutch government open data portal (data.overheid.nl)' with specific resources ('Datasets from national and local Dutch government agencies covering demographics, environment, geospatial data, and public services'). It clearly distinguishes from siblings by specifying the Dutch government data source, unlike other government data tools (e.g., data-australia, 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: for searching Dutch government open data. It mentions the source (data.overheid.nl) and data types covered. However, it does not explicitly state when not to use it or name specific alternative tools for similar data from other countries, though the sibling list shows many country-specific data tools.

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