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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so safety is covered. The description adds useful behavior by naming the return payload (id, sight count, summary, guide URL), but says nothing about the 'limit' cap (max 200, default 25) or truncation semantics on large result sets.

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?

Three short sentences, front-loaded with what is found, then what is returned, then the zero-argument case. No filler or 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?

With no output schema, the description steps in to enumerate return fields, which is the key missing piece for a discovery tool. The only residual gap for a 4-parameter search tool is result-limit behavior.

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 75%, and the description compensates meaningfully: it explains that query matches name, country or region and works across the six languages, and that an omitted query lists everything. The 'limit' parameter remains undocumented in both schema and description, which keeps it below 5.

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?

States a specific verb and resource ('Find covered European cities by name, country or region') and names the returned fields. It also signals downstream use ('the city id needed by the other tools'). It doesn't explicitly distinguish itself from list_countries or search_attractions, so it falls short of a 5.

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?

Gives a clear usage rule — 'Omit query to list all cities' — which effectively also describes the no-argument browse mode. It lacks explicit exclusions or a pointer to a sibling (e.g. when to use list_countries instead), so it is clear but incomplete.

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