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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds one genuinely useful behavioral fact not in annotations: the fixed three-month forward-looking window. However, with an output schema present, the enumeration of return fields adds little, and nothing is said about result size or ordering.

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?

A single tight sentence with the resource front-loaded and the payload listed compactly. The comma-separated metric list is dense but readable, and no sentence is wasted.

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 parameters, read-only annotations, and an output schema documenting the return shape, the description only needs to convey scope and the time window — both are present. Only routing guidance against siblings is missing.

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 tool takes zero parameters, so the schema-level baseline of 4 applies. There is nothing for the description to clarify about inputs.

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?

Names the resource (destinations) and enumerates the aggregate data returned (discounted boat counts, max/median discount, cheapest week, hull split, page link). It is clearly distinct from the singular get_destination sibling. It lacks an explicit verb, but the list semantics are unambiguous.

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 'next three months' window and the discount-centric payload imply this is a discovery/overview tool, but the description never states when to use it versus get_destination, search_deals or prices_by_month. No exclusions or prerequisites are given, leaving the agent to infer routing.

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