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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds context about the data source (WHO/IARC) and the specific statistical measures returned, which goes beyond annotations. It does not contradict any annotation.

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 two sentences: the first front-loads the primary function and data fields, the second gives concrete usage examples. No redundancy or filler, every sentence earns its place.

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?

For a read-only query tool with 3 simple parameters and no output schema, the description covers the data returned (cases, deaths, prevalence, ranked sites), the source, and typical usage contexts. It does not discuss output format or errors, but given the tool's simplicity and annotation coverage, nothing critical is missing.

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 documented (country, sex, limit) including enums and defaults. The description does not add any extra parameter details or clarify behavior beyond the schema, so the baseline score of 3 (schema carries the burden) 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 states 'Cancer statistics for one country from the WHO/IARC Global Cancer Observatory (GLOBOCAN)' and enumerates the exact measures returned: total new cases, deaths, 5-year prevalence, and leading cancer sites ranked with age-standardised rates. This is a specific verb+resource combination, and the examples further clarify scope. It distinguishes itself from sibling GLOBOCAN tools by focusing on a single country profile, though it does not explicitly name alternatives.

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 examples ('how many people get cancer in Japan', 'leading cause of cancer death in Brazil') and states 'or any national cancer burden question', giving clear context for when to use the tool. However, it does not explicitly contrast with sibling tools such as globocan_cancer_in_country or globocan_cancer_types, nor mention when not to use it, leaving some room for ambiguous routing.

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