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

Annotations already declare readOnlyHint=true and openWorldHint=true. The description adds genuinely useful behavioral context beyond them: it states the data is "non-transactional" and that "Booking, checkout, payment, and reservation tokens are never returned," which tells the agent what this call cannot surface. It does not cover pagination or rate-limit behavior.

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?

Four tight sentences, front-loaded with the return scope, then exclusions, then the identifier sourcing and the sibling route. No sentence is 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, the description needn't describe return values, and annotations carry the safety profile. It covers scope, what is excluded, parameter sourcing, and the alternative tool — leaving only minor gaps like pagination behavior.

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 the schema already documents all six parameters, including the property_id sourcing rule. The description's note that property_id comes "from a Search response" largely restates the schema's own hotels_search properties[].id explanation, adding little. Baseline 3 is appropriate.

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 uses a specific verb ("Returns") with a precise resource ("public room/unit offer summaries") scoped to one property and date range. It explicitly distinguishes itself from hotels_rates, which covers a different data surface (rates vs. offer summaries).

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 names the alternative ("Use hotels_rates to get Hotels.com rates for one property") and establishes the context that this tool needs a property id and date range. The when-vs-when distinction between offers and rates is implied rather than spelled out, but the routing signal is present.

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