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

Annotations already declare readOnly, idempotent, closed-world, non-destructive, so the safety profile is covered. The description adds real value beyond that: the 180-night cap, that data comes from the live calendar, and the privacy limitation that reserved nights appear only as 'reserved' without details.

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 short sentences, front-loaded with the core capability, followed by return behavior and the next-step pointer. No filler or redundant restatement of the name.

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?

For a two-parameter read tool with an output schema, the description covers the essentials: source of truth, date-range limit, and result shape. Minor gap is that it does not say what happens for ranges beyond 180 nights or how invalid/past dates are handled.

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 explains that start is the arrival/first night and end is the departure morning. The description adds only the 180-night range constraint, which is not itself a parameter-level detail; baseline 3 applies when the schema does the heavy lifting.

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 and resource ('night-by-night availability from the live booking calendar') plus the exact scope ('between two dates, up to 180 nights') and what it returns. This clearly separates it from siblings like get_quote or suggest_dates, which answer different questions.

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 routes the agent to get_quote for price and minimum stay, establishing the intended call sequence. It gives clear context but does not name a true alternative for availability itself (e.g., suggest_dates for finding open dates), so no exclusion is stated.

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