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

Annotations already mark readOnly, openWorld, idempotent, and non-destructive. The description adds crucial operational context beyond those: 'there is no endpoint that returns every plan for every country' and 'This needs no login.' This explains a real limitation and authentication requirement that annotations do not convey.

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 compact, front-loaded with the core purpose, and every sentence earns its place: WHAT it shows, WHEN to use, IMPORTANT limitation, and NEXT STEP. No filler or repetition of schema fields.

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 0-required-parameter tool with a rich output schema and strong annotations, the description covers all needed context: what result looks like, usage triggers, endpoint limitation, and follow-up action. It also names the no-login requirement. Sibling tools provide further avenues but are not necessary to enumerate.

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 covers 100% of parameters with clear descriptions for locale ('Optional language tag for platform text, e.g. 'en') and currency ('Optional ISO-4217 currency code, e.g. 'USD'). The description does not repeat or add param syntax, which is acceptable because the schema already carries full weight, so baseline 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 clearly states a specific action and resource: 'Show what the catalogue offers: how many destinations and regions exist, plus a few cruise and global plans.' It distinguishes itself from siblings by explicitly noting that there is no endpoint returning every plan, making its overview role distinct from country/region-specific tools like find_bundles_by_country and list_regions.

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 WHEN clause gives explicit triggers: 'user asks something broad like "show me all bundles", "what do you have" or "what plans are there".' It also provides a when-not ('never claim to be showing all of them') and guides the next step: 'ask which country or region the user is travelling to, or whether they want a global or cruise plan.' It even notes login not required, which is a precondition statement.

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