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

With no annotations, the description carries the full burden of behavioral disclosure. It adds a concrete behavioral limit ('Returns up to 20 results'), which is useful, but it does not disclose behavior like whether the 'active_only' filter is applied by default, sorting, or pagination.

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 very concise and front-loaded, using a single sentence with no filler. It is appropriately sized for a simple search tool, though it could have included a bit more parameter context without becoming verbose.

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?

Given the tool's moderate complexity (3 params, 1 required) and the presence of an output schema, the description covers the core search purpose and result limit. However, it omits the optional filtering parameters' behavior and offers no sibling differentiation, leaving some gaps for an agent deciding among similar tools.

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 0%, so the description must compensate for explaining parameters. It only adds meaning to the 'query' parameter ('by name'), while the 'country' and 'active_only' parameters remain unexplained, leaving a significant semantic gap.

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 action ('Search') and the resource ('airlines'), with a specific filter ('by name'). It is precise but does not explicitly distinguish this tool from the sibling 'airlines_lookup', so it falls short of a perfect 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?

The description provides no guidance on when to use this tool versus alternatives like 'airlines_lookup' or when to prefer other search tools. There is no mention of suitable contexts, prerequisites, or exclusions.

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