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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the read-only nature is covered. The description adds behavioral detail beyond annotations by specifying that the default response includes the first 10 stays and the total count, and that setting detail to 'full' returns all stays. This gives the agent insight into pagination and response size, which is not in the annotations. No contradiction is present.

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 a single, tight sentence that front-loads the core purpose ('One destination and its stays') and immediately explains the key behavioral variation (default vs 'full' detail). There is no redundant wording, and every clause contributes essential information. It is an excellent example of concise, structured description.

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 tool with an output schema and fully documented parameters, the description covers the main behavior: retrieving a destination and its stays, with a clear explanation of the detail parameter's effect on response size. It doesn't mention the country parameter's role in slug collisions, but that is documented in the schema. The description is sufficient for an agent to call the tool correctly without needing additional context.

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 provides 100% coverage with descriptions for all three parameters, including the effect of the detail enum and the country parameter for disambiguation. The description adds a small extra layer by linking the detail parameter to the number of stays returned (first 10 vs all), which is not explicitly in the schema. However, this is a modest addition; the schema already does most of the work, so a 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 the tool returns 'One destination and its stays', which clearly identifies a single-resource retrieval with associated stays. It distinguishes from list_destinations by implying a single destination, and from get_stay by including stays. The detail parameter behavior is also mentioned, adding specificity. However, it doesn't explicitly name sibling tools, so differentiation is implicit rather than explicit.

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 provides no guidance on when to use this tool versus alternatives like list_destinations or get_stay. It doesn't state conditions for selection, such as needing a specific destination's details or stays. There are no exclusions or mentions of other tools, leaving the agent to infer usage context from the tool name and schema alone.

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