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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the description is freed to add operational detail. It does: results respect a typical minimum-stay rule, and only the first few windows carry live all-in totals, which sets expectations about partial pricing data.

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: the first defines the output and filters, the second defines the usage context. Front-loaded and free of filler.

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 an output schema present, return shape need not be explained, and the description still flags the key quirk that only the first few windows include totals. Minor residual gap around how many windows are returned per month.

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 month format, guest count, and nights are already documented; the baseline applies. The description maps 'requested length' to nights but adds nothing about the guests cap of 2 or how nights bounds interact with the minimum-stay filter.

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 and resource: lists open stay windows for a given month, filtered by length and typical minimum stay, with live all-in totals for the first few. An agent can distinguish this from get_quote or check_availability by the 'open windows' framing, though no sibling is named explicitly.

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 a concrete usage trigger with an example: 'Use it when the guest is flexible ("a long weekend in February")'. This clearly implies the alternative (exact-date availability checking) without naming it or stating an explicit exclusion.

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