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

Annotations already cover read-only/idempotent safety, and the description adds substantial behavioral context beyond them: the exact FCDO and US advisory level scales, absence of FCDO data for the UK and State data for the US with a caveat rather than a fabricated level, exclusion of doubly-unknown countries from rankings, and the mandatory disclaimer prefixed to every response.

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?

Front-loaded with the one-line purpose, then the mode rules, then caveats and disclaimer. Dense but each clause carries operational information; the disclaimer sentence is slightly verbose but is arguably required context for this dataset.

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 need not explain return shapes, and it instead covers sourcing, grading differences between governments, missing-data behavior, and the informational-use disclaimer. Nothing an agent needs to call or interpret this tool 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 coverage is 100%, so the baseline is 3, but the description adds real meaning: it explains that `sort=highest` inverts the default ranking, that `countries` is ignored when `country` is present, and the ISO alpha-2 expectation for `country`. Only `limit` is left to the schema alone.

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?

Opens with a specific verb+resource ('What two governments say about going') and names both sources (UK FCDO, US State Department) and the exact artifacts returned per country. An agent can tell this apart from siblings like compare_country_risk or health_prep without inspecting schemas.

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?

Explicitly maps the three invocation modes: `country` for one country's full advice, `countries` (two or more) for a side-by-side, and neither for the 41-country spine ranking with `sort` direction. The precedence rule ('`countries` ignored when `country` is given') is stated, leaving nothing to inference.

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