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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds genuine value by enumerating the fields returned, which matters because no output schema exists, but says nothing about result ordering, pagination, or the default limit behavior beyond what the schema states.

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 short sentences with no filler, and the resource plus field list is front-loaded before the filtering note. Slightly dense in its comma-separated field enumeration but nothing is wasted.

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?

For a two-parameter read-only listing tool with no output schema, the definition covers what is returned and how to filter, which is close to sufficient. Ordering of results and pagination behavior are the only notable omissions.

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 both parameters are already documented in the schema. The description restates the query filter, though it narrows it slightly ('name or code') compared to the schema which also includes slug. No additional syntax or matching behavior is explained, so baseline 3 applies.

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 names the resource (airlines) and enumerates the returned fields (IATA code, slug, founding year, closure date, rating, page link), which distinguishes it from get_airline by being a multi-record listing. It does not name the siblings get_airline or top_airlines to route the agent, so it is clear but not differentiated.

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 sentence 'Filter by a fragment of the name or code' implies the lookup use case, but there is no explicit statement of when to use this versus get_airline (single record) or top_airlines (ranked list). Usage is only inferable from the name and field list.

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