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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive. The description adds valuable behavioral context by explaining what fishing events capture (slowed maneuvering, coordinates, area codes) and what port visits include, plus pagination behavior. It does not discuss error handling or rate limits, but this is adequate given the 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, efficient paragraph. It leads with the main purpose, then details event types, then pagination, then the prerequisite. Every sentence earns its place; there is no redundancy or fluff.

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 that an output schema exists and annotations cover the safety profile, the description covers all operational essentials: event types, pagination, and how to obtain the vessel_id. An agent has everything needed to call 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 description coverage is 100%, so the baseline is 3. The description adds some value by explaining event_type semantics and mentioning offset for pagination, but most parameter details are already in the schema. It does not compensate substantially beyond what the schema provides.

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 states a specific verb and resource: 'Retrieve AIS-detected maritime events for a specific vessel'. It distinguishes from sibling tools by focusing on vessel-specific events and explicitly mentioning that the vessel UUID comes from gfw.vessel.search. The scope is unambiguous.

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 clearly states a prerequisite ('Vessel UUID is obtained from gfw.vessel.search') and explicitly mentions pagination with offset. It does not explicitly name alternative tools or when-not-to-use conditions, but the context and phrase 'for a specific vessel' imply appropriate use cases. Lacks explicit exclusions.

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