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

The description's verb 'Discover' aligns with the readOnly and idempotent annotations, and no side effects are implied. While it does not add much behavioral detail beyond the annotations, it does not contradict them and reinforces the non-destructive nature.

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, compact sentence that lists the key returned categories in a clear sequence. There is no fluff or redundancy, and every phrase adds useful information.

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 an output schema present, the description does not need to detail the return structure. It names the main dimensions returned (supported countries, per-operation coverage, evidence, dataset versions, request limits) and gives a clear use case, making it complete enough for an agent to decide to call it.

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?

The schema has no parameter descriptions, and the description only loosely maps to the parameters: 'supported countries' hints at countryCode and 'per-operation' hints at operation. It does not explain optionality, allowed values, or how the parameters affect the result, so the description does not compensate for zero schema coverage.

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: to discover supported countries, per-operation review coverage, evidence, dataset versions, and request limits. This is distinct from the sibling tools, which perform analysis, comparison, normalization, or diagnostics rather than capability discovery.

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 phrase 'before choosing a phone workflow' gives a clear temporal and contextual trigger for when to use this tool. It does not explicitly name alternatives or exclusion criteria, but the intended use case is sufficiently clear.

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