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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds meaningful behavioral context: the instruction to always present the page URL as a clickable link, unchanged, and the warning that it is the only way to book or buy. This goes beyond the annotations by informing the agent of a critical output-handling requirement, justifying a score above the baseline.

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?

The description is two sentences with zero redundancy. The first sentence concisely enumerates the content and origin, and the second sentence delivers an essential, action-focused instruction about URL handling. Key information is front-loaded, making it easy to scan.

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 fully covers what an agent needs to invoke the tool correctly: it states the source of the key, the list of returned details, and the critical URL requirement. Since an output schema exists, the return format is already documented, and the read-only annotations cover side-effect concerns. No gaps are apparent for a simple hotel-details lookup.

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 80% (only 'adults' lacks a description). The description does not elaborate on any parameters beyond what the schema already provides. It mentions hotel_key and its origin, which matches the schema description. Since the schema does most of the work and the description adds no extra detail for parameters, the baseline of 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 states a specific verb ('get') and resource ('hotel details'), enumerates the exact fields returned (address, description, amenities, photos, check-in/out times, places nearby, guest opinion summary, page URL), and explicitly ties the tool to 'search_hotels' via hotel_key. This clearly distinguishes it from sibling tools like get_property or get_vehicle, which serve different entity types.

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?

The description implies the correct usage path by specifying that the hotel_key comes from search_hotels, indicating the caller must first perform a search. It does not explicitly name alternatives or state when not to use this tool, but the context (a detailed hotel lookup) is clear enough for an agent to route correctly. Slight deduction for lack of explicit exclusionary guidance.

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