Katzilla MCP

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

The description adds valuable behavioral context beyond annotations: it discloses the data source ('WHO GHO'), update frequency ('updates daily'), licensing ('CC-BY-NC-SA 3.0 IGO'), and return format ('Katzilla envelope { data, quality, citation }'). While annotations cover read-only, non-destructive, idempotent, and open-world hints, the description provides practical implementation details that help the agent understand what to expect.

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 three sentences: purpose statement, parameter guidance, and return format details. Every sentence adds essential information with zero waste. It's front-loaded with the core functionality and progressively adds important details.

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, comprehensive annotations, complete schema coverage, and existence of an output schema, the description provides excellent contextual completeness. It covers purpose, usage, behavioral traits, data source, licensing, update frequency, and return format - everything needed for effective tool selection and invocation.

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?

With 100% schema description coverage, the baseline is 3. The description enhances this by explaining the parameter's dual purpose: 'List all indicators or fetch data for a specific indicator code' and providing an example code ('WHOSIS_000001'). It adds semantic meaning about how the parameter value affects tool behavior beyond the schema's technical 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 clearly states the tool's purpose with specific verbs ('Query', 'List', 'fetch') and resources ('WHO Global Health Observatory (GHO) OData API', 'indicators', 'data for a specific indicator code'). It distinguishes from siblings by specifying it's for health/medical data from WHO, unlike other health tools like CDC or NIH sources.

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 explicit usage guidance: 'List all indicators or fetch data for a specific indicator code' and specifies the parameter behavior ('Use 'Indicator' to list all available indicators'). It clearly indicates when to use which mode based on the indicator parameter value.

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