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

Beyond the readOnlyHint=true annotation, the description discloses two useful behaviors: with no arguments it returns a listing of all guides with topic ids and one-line summaries, and the language parameter only changes the returned URL while the guide text stays English. This adds concrete behavioral context that an agent cannot infer from the schema or 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?

The three functional parts are front-loaded and each sentence earns its place: main action, no-arg listing behavior, and language behavior. The list of topics in the first sentence is a bit long but provides useful scoping without redundancy.

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 no output schema, the description covers what the agent needs to know: it returns full guide text, a listing mode with topic ids and summaries, and a language-dependent URL. Combined with the readOnly annotation and detailed schema, nothing critical is missing for a two-optional-parameter read-only 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?

The input schema already covers both parameters with 100% description coverage, so the baseline is 3. The description adds value by explaining the no-arg behavior for topic (list all guides) and clarifying that language controls only the URL, not the guide text, which goes beyond the schema's individual parameter descriptions.

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 opens with 'Return the full text of one HotelRefund reference guide', which is a specific verb+resource. It enumerates the covered topics and is clearly distinct from sibling tools like get_hotel_price_calendar or get_price_history, which address pricing data, not refund guidance.

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 gives clear usage context: it is for guides about bookings that already exist, and instructs 'Call without arguments to list every guide'. It does not explicitly say when not to use this tool or name sibling alternatives, but its context is sufficient to differentiate it from the pricing-focused siblings.

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