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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so safety profile is clear. Description adds behavioral context: it searches tracked airports and returns IATA codes, which aligns with annotations. No contradiction.

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, front-loaded, no redundant information. Every sentence contributes to understanding the tool's purpose and usage.

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 simplicity and the presence of annotations and output schema, the description covers purpose, input, expected result (matching IATA codes), and relationship to sibling tool. No gaps.

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% with a single parameter 'query' described. Description adds value by providing concrete examples (London, Paris, Chicago, ORD) and clarifying accepted input types: airport code, city, or airport name.

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?

Description clearly states the verb 'Search', the resource 'supported airports', and the context 'when a user's airport reference is ambiguous'. It distinguishes from sibling tools by noting it returns IATA codes for use with airport.get_delay_status, and mentions it's an alias of search_supported_airports.

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?

Description specifies when to use: when an airport reference is ambiguous, and what to do with results: use with airport.get_delay_status. It does not explicitly state when not to use or compare with non-sibling alternatives, but provides clear guidance.

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