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

Annotations already mark readOnlyHint=true and destruptiveHint=false. The description adds valuable context: data snapshot date, output structure (counts per category), and the extra list of differing destinations for 2 passports (up to 30). No contradictions.

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 a single efficient sentence covering purpose, input range, output details, data source, and an example. Every sentence earns its place with no redundancy.

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?

Despite lacking an output schema, the description fully explains the output (counts for categories, and for 2 passports a list of differences up to 30). It also provides the data source and date, making it complete for a simple one-parameter tool.

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% (parameter description explains formats). The tool description reinforces with an example and adds behavioral context like the data snapshot and special case for 2 passports, enhancing meaning beyond the schema.

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 'Compare passport power' with specific resource and scope (2-5 passports, categories like visa-free, on arrival, etc.). It distinguishes from siblings like 'visa_free_destinations' and 'visa_requirement' which are single-passport tools.

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 tells when to use this tool (for 2-5 passports) and mentions the special behavior for exactly 2 passports. It does not explicitly list when not to use or alternatives, but siblings are implicitly differentiated.

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