Find eSIM plans for cruises

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

Beyond the readOnlyHint/idempotentHint annotations, the description discloses that each plan covers specific ships, that the summary only reports a count, and that get_bundle_details is needed to name ships. It also states 'This needs no login,' adding auth context not present in the annotations. No contradictions with 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?

Four short sentences with a clear WHEN marker make the content scannable and front-loaded. Every sentence earns its place: purpose, triggers, ship-coverage caveat, and auth note.

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?

Given 8 optional parameters, rich schema descriptions, a present output schema, and strong annotations, the description covers the remaining context: when to use, ship-specific behavior, and login requirements. No major gaps remain for an agent to invoke the tool correctly.

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 provides 100% description coverage, including usage guidance like 'Only pass a budget the user actually stated' and 'Set true only when the user explicitly asks.' The tool description itself adds no parameter-level semantics, so the schema-heavy 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 opens with a specific action and resource: 'List the eSIM plans sold for cruise ships.' This clearly distinguishes it from country/region bundle finders and identifies the maritime domain. The title reinforces the purpose, and the special-case mention of get_bundle_details further clarifies scope.

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 states explicit trigger conditions ('user says they are going on a cruise, names a ship or a cruise line, or asks for maritime coverage'), and directs the agent to get_bundle_details when a specific ship is involved before promising coverage. It also notes no login is required, which helps with alternative handling.

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