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

readOnlyHint=true already establishes the safety profile, so the description's added value is disclosing the return shape (per-date true/false) and the endpoint mapping — genuinely useful given there is no output schema. It omits pagination behavior even though a page parameter exists.

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 the most load-bearing fact (the endDate convention) front and center. The endpoint-string sentence is mildly redundant but costs almost nothing.

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?

With no output schema, the description does well to state the boolean-per-date return. But it says nothing about pagination or how the mix of optional filter parameters (dates, roomIds, propertyIds) behaves when omitted, which matters for a 5-parameter, 0-required 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 description coverage is 100%, so all five parameters are already documented. The description restates the endDate/last-night convention without adding format or edge-case detail beyond the schema, 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+resource+output form: per-date boolean availability for rooms across a night range, and even names the backing endpoint. It does not, however, differentiate itself from close siblings such as beds24_get_room_calendar or beds24_get_room_offers, so an agent must infer the boundary.

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?

No when-to-use guidance, no conditions for choosing this over get_room_calendar or get_room_offers, and no note on how the optional filters (roomIds vs propertyIds) should be combined. The endDate clarification is a parameter detail, not usage guidance.

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