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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description contributes the ordering guarantee ('newest first') and what each item contains, but says nothing about result volume, default limit, or pagination behavior.

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?

One sentence, front-loaded with the resource and ordering, then the three access patterns. The nested parentheticals make the middle clause slightly dense, but nothing is redundant or padded.

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?

There is no output schema, and the description does compensate by describing item structure (ship or line plus page link). However, for a feed tool with no required parameters and a limit capped at 200, the absence of any default-limit or result-size guidance leaves a meaningful gap.

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 only 50%, yet the description usefully disambiguates the hardest point: 'line' returns that line's stories plus its ships', while 'subject' + 'ref' narrows to one entity's own stories. It leaves 'limit' entirely unexplained and does not map the cruise_line/cruise_ship enum values to concrete query behavior.

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 resource (cruise news) with sort order ('newest first') and the shape of each returned story ('the ship or line it covers and that page's link'). The cruise scope implicitly separates it from the sibling list_news/search_news, though it never names those alternatives outright.

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?

Enumerates the three operating modes clearly: the whole feed with no filters, one line's news via 'line', or one subject's own stories via 'subject' + 'ref'. That is real when-to-use guidance for parameter combinations, but there is no explicit exclusion telling the agent when to reach for search_news instead.

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