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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds that the data is 'public' and sourced from the listing's bootstrap data, which is modest extra context but says nothing about freshness, granularity, or coverage of the calendar hints.

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 tight sentences with zero waste: the purpose leads, then the routing guidance follows. Every clause carries load and it is appropriately front-loaded.

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 detail is unnecessary, and annotations cover the safety profile. The description handles purpose and tool routing adequately, with the only residual gap being the exact nature and freshness of the 'calendar month hints'.

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% with a single required 'id' parameter that is fully documented. The description echoes the requirement of a known listing id but adds no format or syntax detail beyond what the schema provides, so the 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?

States a specific verb (Fetch) and resource (calendar month hints from an Airbnb listing's bootstrap data). It clearly situates itself relative to airbnb_search and airbnb_room, so an agent can distinguish it from siblings. The phrase 'calendar month hints' is slightly idiosyncratic but still concrete.

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?

Explicitly names the two alternative tools and the workflow prerequisite: use airbnb_search to find a listing and airbnb_room for its details, then choose this tool for calendar hints given a known id. The selection condition is stated with nothing left to inference.

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