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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description usefully adds that results are cities only, never airports, but says nothing about match behavior, locale effects, or result ordering. Adequate but not rich.

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?

Two sentences, no filler: the core action leads and the scope caveat follows immediately. Every clause earns its place.

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, return values need not be described, and the prerequisite usage plus the cities-only constraint cover the essentials for a simple three-parameter lookup. Only minor behavioral context (fuzzy matching, locale handling) is absent.

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%, so query, limit, and locale are each documented in the schema itself. The description adds no parameter-level detail beyond what is already structured, which is the correct baseline when the schema does the lifting.

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 ('resolve a city name into its corresponding city IATA code') and immediately scopes it with 'It returns cities only, not individual airports.' An agent can distinguish this lookup from the price and analytics siblings without opening any schema.

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 an explicit readiness condition: call this before any route price, monthly price, or airport analytics tool that needs a city code, which maps onto the sibling set. It lacks named alternatives or a when-NOT case, but the prerequisite framing is clear.

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