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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description's only added behavioral content is the 'real availability vs. type existence' distinction, which is useful but modest. No mention of permissions, rate limits, or result shape.

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 no filler; the availability distinction is front-loaded and the prerequisite call is the trailing actionable instruction.

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?

There is no output schema, so the description carries some return-value burden — it does indicate the result is which physical rooms are actually free, which is the key semantic. It stops short of describing the result structure (e.g., per-room list vs. aggregate count), a minor gap for a 4-param read tool.

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 only 50%, with restaurantId and roomFacilityTypeId undocumented in the schema. The description partially compensates by explaining where roomFacilityTypeId comes from (list_room_types), but adds nothing about restaurantId, and checkIn/checkOut semantics are fully covered by the schema.

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?

Specific verb (check) plus resource (physical rooms/facilities of a given catalog type) and an explicit scope qualifier: 'real availability, not just that the type exists.' This distinguishes it cleanly from the sibling list_room_types and from check_event_availability/check_service_availability.

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 states the prerequisite: 'Use list_room_types first to get roomFacilityTypeId.' The 'not just that the type exists' clause further clarifies the boundary with that sibling. It doesn't, however, say anything about when to book (book_room) versus just check, so the routing guidance is strong but not exhaustive.

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