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

Annotations already declare readOnlyHint and idempotentHint, and the description adds meaningful behavior: matching over 18 languages, slug, or ISO code, empty-query returning all items, and the meaning of each returned field (min_retail, unlimited_from, plan_count). Minor omissions like pagination and ordering are acceptable for a simple search tool.

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?

Three sentences, each dense with information: listing semantics, query behavior, output fields, and the next-step call. There is no filler or repetition of schema content.

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 one-parameter, read-only tool with an output schema, the description covers search behavior, return-field semantics, and the natural follow-up call. An agent has everything needed to invoke it correctly and interpret the result, aided by the output schema.

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 schema has 0% description coverage, so the description fully carries the burden for the single `query` parameter. It explains matching across name, slug, and ISO code, and explicitly states that an empty value lists everything. This is complete semantic coverage for the parameter.

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 identifies the resource (destinations) and the search/list behavior: query matches name in 18 languages, slug, or ISO code, and empty query lists everything. The opening phrase 'Destinations on sale' is slightly ambiguous (could be read as discounted items) and the verb is not explicitly stated, though the tool name supplies it. It differentiates from siblings by naming get_plans as the follow-up.

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?

It gives a clear usage pattern: pass a query to search, leave empty to list everything, and continue with get_plans(slug). It also provides concrete field-level context. It does not state explicit exclusions or when to prefer siblings over this tool, but the continuation guidance anchors when this tool is the right entry point.

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