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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds useful scope context ('only returns descriptive information') but says nothing about ordering, pagination, or how many photos are returned beyond what the output schema likely provides.

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 tightly written sentences; the purpose is front-loaded and the scope exclusion follows as a guardrail. Nothing is wasted or redundant.

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, full schema coverage and rich annotations, the description only needs to establish purpose and scope, which it does. Minor gap: no hint about result size or ordering, though that is a small omission for a read-only gallery tool.

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 hotel_id, language (with enum and French fallback) and cover_only. The description only gestures at the cover limitation and captions, adding little beyond what the schema provides – baseline 3 applies.

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 ('Return the photo gallery of a hotel') and even names the payload ('URLs and captions'), which clearly separates it from get_amenities, get_hotel_details and search_hotels. It stops short of explicitly naming siblings or contrasting them, so it lands just below the top band.

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 second sentence gives a clear scope exclusion ('No availability, rates or booking'), which tells the agent when this tool is not the right one and implicitly routes booking intent elsewhere. It does not explicitly name alternative siblings for the photo case, but the context is clear.

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