get_city_directions

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is fully covered by structured data. The description adds useful context that results include fares and dates, but discloses nothing about pagination, result limits, or currency behavior beyond what's in the schema.

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 tight sentences, front-loaded with the core action and immediately followed by routing guidance. No filler or repetition of schema content.

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?

An output schema exists, so return-value details need not be spelled out; the description covers action, scope, and sibling routing for a two-parameter read-only tool. Nothing an agent needs to select or call it is missing.

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 (origin IATA, currency) are already documented in the schema, including the pointer to lookup_cities. The description's 'from a city' adds no meaning beyond the schema's 'Origin city IATA code'.

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 ('List the cheapest destinations reachable from a city') plus scope ('with a fare and dates'), and explicitly distinguishes itself from the similarly-named siblings get_popular_directions and get_alternative_directions.

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 when-to-use condition ('user asks where they can fly from a city, or wants somewhere cheap without naming a destination') and routes to named alternatives (get_popular_directions for inbound, search_flights/get_prices_calendar for pricing a chosen route).

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