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

Beyond the readOnlyHint and idempotentHint annotations, the description discloses what the tool actually returns: month-by-month averages, the warmest and driest months, and a possible list of sub-region choices. This is substantial behavioral context, especially important because no output schema exists.

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?

Two sentences with no filler: the first states the core output, and the second covers the conditional list behavior. The most important information is front-loaded and every sentence earns its place.

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 simple, one-parameter, read-only tool with no output schema, the description sufficiently explains what result to expect and when a list result may occur. There is no missing critical information that would prevent an agent from selecting or invoking 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 schema fully documents the single 'place' parameter, including its type, required status, and an example. The main description reinforces that the place can be a port, region, or destination and adds sub-region behavior, but it does not add much beyond the schema's own parameter description, so the high-coverage baseline of 3 applies.

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 names a specific verb-resource pair: obtain month-by-month average temperature and rainfall for a cruise port, region, or destination, plus the warmest and driest months. This clearly distinguishes it from the ship-focused and itinerary-focused siblings like getShipProfile, getCabinDetail, and searchCruises.

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 clearly states the intended input scope — a cruise port, region, or destination — and explains the behavior for places with very different sub-regions, which guides how the tool should be used. It does not explicitly name alternative tools or exclusions, but the weather-climate purpose provides clear context.

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