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

No annotations are provided, so the description carries the full behavioral burden. It implies a read-only aggregate and hints at the return shape ('grouped and counted'), but says nothing about whether the passport is required, whether results are ranked, what visa categories exist, or any rate/auth constraints.

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?

A single, front-loaded sentence with no filler; the aggregation behavior is the most useful part and is not buried. It is arguably too terse for the gaps it leaves, but nothing in it is wasted.

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?

With no output schema, the description usefully sketches the return shape ('grouped and counted by visa category'), which is more than most one-liners offer. However, for a lookup tool with an undocumented parameter format and no annotations, it falls short of what an agent needs to call it confidently.

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 coverage is 0% and the single required parameter 'passport' has no type detail beyond string and no documented format. The phrase 'on one passport' hints at a single value and implies a country/entity identifier, but the description never states the expected format (ISO code, nationality name, etc.), leaving a real ambiguity for the agent.

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 a specific resource (destinations reachable on a passport) and a specific output shape (grouped and counted by visa category), which distinguishes it from siblings like visa_lookup and list_destinations. It stops short of explicitly naming those siblings, so the differentiation is implicit rather than stated.

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?

There is no when-to-use guidance, no when-not-to-use, and no reference to any alternative tool, despite four sibling tools that overlap conceptually (visa_lookup, list_destinations, list_nationalities, extension_rules). An agent must infer the use case entirely from the description sentence.

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