vessels_watched

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

With no annotations, the description carries the full behavioral burden, and it does so excellently. It discloses the 30-minute retention of stale vessels, the deliberate filtering to watched regions, and the no-subscription fallback that returns everything with a note, all of which an agent must know to interpret results correctly.

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?

The core behavior is front-loaded in the first sentence, and the later paragraphs explain important edge cases rather than restating the schema. Some editorial phrasing is a bit verbose, but the length is justified by the subtle behavioral context it communicates.

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?

Given the single optional parameter, a rich schema description, and an output schema, the definition covers the important edge cases: stale deselected-region vessels, no-subscription behavior, and truncation visibility. An agent has enough information to invoke and interpret 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?

Schema coverage is 100%, and the limit parameter already has a thorough description including default, maximum, and truncation visibility. The tool description adds no additional parameter-level meaning, so the baseline of 3 is appropriate.

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 opening line, 'Vessels inside the regions currently being watched, and nothing else,' states a specific resource and scope with a clear contrast to broader vessel queries. It also clarifies the semantics against siblings by explaining that deselected regions' vessels must not be shown.

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 establishes clear context: this tool should reflect only currently watched regions, and if no live subscription exists, no filter applies and everything is returned. It does not explicitly name sibling alternatives as 'do not use this for X,' but the intended usage is unmistakable.

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