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

Annotations already cover readOnly/idempotent/closed-world, so the bar is lower; the description still adds real traits: result ordering (busiest first), the UN/LOCODE as identifying key, and which cross-domain aggregates (ships based there, airport lounge counts on Lounge Frog) appear in each row. It does not discuss pagination or cost of large limits, which keeps it below 5.

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?

Front-loaded with the core purpose and sort order, which is good, but it collapses into a single long colon-delimited run-on enumerating output fields, making it harder to scan than short separated sentences would be.

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, describing the returned fields is genuinely necessary and the description does that thoroughly, including the guide-availability flag. The remaining gap is disambiguation from list_cruise_port_catalog and list_cruise_regions, which an agent comparing siblings would want.

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 100% and both parameters (limit with 1-100 range and default 30, query matching city/airport/terminal names) are fully documented in the schema. The description adds no syntax, matching behavior, or example beyond what the schema already says, so baseline 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?

States a specific verb+resource: ports cruise ships sail from on Cruises Frog, with explicit sort order ('busiest first') and identity key (five-character UN/LOCODE). The parenthetical '(get_cruise_port_guide)' points to the detail sibling, but the description never distinguishes this list from the similarly named sibling 'list_cruise_port_catalog', leaving one likely confusion unresolved.

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?

Implicitly routes the agent: use this to enumerate ports, use get_cruise_port_guide for the full guide. There is no explicit when-to-use vs list_cruise_port_catalog or list_cruise_regions, and no statement about whether the optional 'query' filter is the intended way to look up a single port.

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