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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint, so safety is covered. The description adds genuinely useful context beyond them: the data comes from the ports' own published schedules, and posted departure times exist only for Miami and Canaveral — a data-completeness caveat an agent would otherwise miss.

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, front-loaded with what the tool returns and what it covers, followed by use cases. The first sentence is long and parenthesis-heavy (port-by-port viewing spots), which is dense but each clause carries real information.

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?

With no output schema, the description carries the burden of describing returns and does so: which ships leave which port, the posted departure time where available, and when each passes named viewing spots. Combined with the annotation safety profile, an agent has enough to decide and call 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?

Schema coverage is 67%, and the description compensates by mapping the natural-language scope onto the enums: it names all four ports that correspond to the `port` enum and enumerates today/tomorrow/this week for `when`. The numeric `days` parameter (1–14) is never mentioned, and the interaction between `days` and `when` is left unexplained.

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?

Names a concrete resource (cruise ship sail-aways) and bounds it tightly to four named Florida ports, three time horizons, and specific viewing spots. The scope is unmistakable, though it never explicitly distinguishes itself from near-neighbors like debark_day or shore_day.

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?

Gives three concrete use cases in quoted/intent form ('can we watch the cruise ships leave', sail-away parties on land, family waving off), which covers the when-to-use question well. It stops short of stating exclusions or naming an alternative tool for schedule/port questions that fall outside this one.

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