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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered. The description adds value by specifying the scope of information (comfort, safety score, wifi, car rental) beyond the annotations. No contradictions or hidden side effects are mentioned, which is appropriate for a read-only operation.

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, front-loaded sentence that immediately states the resource type and then lists specific topics. No wasted words, and the key information is presented in an efficient, scannable manner.

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 read-only guide with one parameter and no output schema, the description covers the content scope well. It doesn't mention output format (text vs structured) or error handling for unknown ports, but given the low complexity and existing annotations, these omissions are minor. The description is effectively complete for an agent to decide whether to call it.

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 supplies full parameter documentation with 100% coverage and an example ('Cozumel'). The description does not add extra syntax or constraints, which is acceptable given the schema's completeness. Baseline 3 is appropriate when the schema already carries the parameter meaning.

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 states a specific verb ('get') and resource ('port guide') and enumerates the covered topics (beaches, shopping, terminals, etc.), which clearly distinguishes it from sibling tools like getPortExcursions and getBestTimeToVisit. The agent can identify exactly what this tool returns without ambiguity.

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 implicitly signals that this is the general-purpose port guide, as opposed to siblings focused on specific aspects (excursions, timing, cabins). There is no explicit 'use for X, not for Y', but the content list makes the intended use inferable. A slight boost for clarity, but it lacks an explicit contrast with alternatives.

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