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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so safety is covered. The description adds useful behavior beyond that: the window defaults to today and is capped at 24 months, and it discloses the shape of the returned per-day data. It stops short of noting rate limits, error cases, or how unbookable days are represented.

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, zero filler. The returned-field enumeration comes first and the window behavior second, so the most decision-relevant information is 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?

With no output schema, the description carries the burden of describing the return value, and it does so by listing the per-day fields. Combined with the window default/cap rules and full schema coverage, an agent has enough to call it correctly; only edge-case behavior (empty windows, unavailable days) is unaddressed.

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% and the schema already documents id, from, and to including formats. The description adds meaning not present in the schema, specifically the default window start (today) and the 24-month maximum span, which constrains how the from/to pair should be used.

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?

The description names a specific resource (per-day availability for one accommodation) and enumerates the returned fields (bookable days, arrival/departure flags, minimum stay, price, discounts), so the agent knows exactly what it retrieves. It does not explicitly contrast itself with siblings like get_accommodation or search_accommodations, though the resource scope makes the distinction inferable.

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?

It states the default window (today) and the 24-month cap, which is genuine operational guidance for calling it. However, it never says when to prefer this over get_accommodation or search_accommodations, nor any exclusions or prerequisites, so usage is only implied.

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