get_vessel_last_port_event

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It indicates a read operation ('Get') but does not explain behavior in edge cases (e.g., no events found, invalid vessel ID), whether the result is a single event or a list, or what fields are returned. This is insufficient for a tool with no schema annotations.

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 description is a single concise sentence that fully conveys the core action without any unnecessary words. It is front-loaded and efficient, earning the highest score for conciseness and structure.

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?

The tool is relatively simple with only two parameters, and the description adequately captures the primary intent. However, since there is no output schema, the description does not specify the shape or content of the returned event, which would improve completeness. Given the simplicity, this is still acceptable but leaves some ambiguity.

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 schema description coverage is 100% as both parameters (idType and vesselId) have descriptions in the schema. Per the rubric, when coverage is high, the baseline score is 3. The tool description itself adds no extra meaning to the parameters beyond what the schema already provides, so no bonus is warranted.

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 clearly states the tool's purpose: getting the most recent port event (arrival or departure) for a vessel. It uses a specific verb and resource, making the purpose unambiguous. However, it does not explicitly differentiate from sibling tools like get_port_events_by_vessel or list_port_events, so it misses the full mark for sibling distinction.

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 provides no guidance on when to use this tool versus alternatives. It offers no context about scenarios where this tool is preferred or when other tools should be used. There is no mention of exclusions, prerequisites, or alternative approaches.

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