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

Annotations already mark the tool as read-only and non-destructive, and the description adds useful behavioral detail: it returns per-checkin-date nightly rates and supports day-of-week pattern discovery. Nothing in the description contradicts the annotations.

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?

Three sentences front-load the core behavior, then give the usage trigger, then explain the value of the returned data. The third sentence slightly overlaps with the first, but it earns its place by clarifying why the calendar-style output matters.

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?

The description, combined with 100% schema parameter coverage and an output schema, gives an agent everything needed to select and call this read-only tool correctly. No critical guidance about return behavior or prerequisites is missing.

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%, so the baseline is 3 and the description need not repeat parameter docs. It adds only a light semantic gloss about date range and per-checkin-date output, without enriching the meaning of the `nights` parameter beyond 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?

The description clearly states the operation: fetching a rate calendar for a hotel over a date range, with the purpose of recommending cheapest nights. It implies a distinction from siblings through the flexible-dates use case, but it does not explicitly name or rule out alternative tools.

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 gives an explicit trigger: use when a user has flexible dates such as 'any week in May.' It does not list exclusions or alternatives, but the intended context is clear and actionable.

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