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

Annotations already establish that this is a read-only, open-world, non-idempotent, non-destructive operation. The description adds useful temporal context by noting current versus past-moment queries, but it does not describe data freshness, rate limits, or return 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?

The description is a single concise sentence with the resource and temporal scope front-loaded. It avoids filler, though the fragmentary phrasing leaves some ambiguity about the exact operation.

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, an undocumented generic 'input' parameter, and no detailed usage guidance, the definition is too sparse for an agent to call the tool confidently. It needs to explain the expected input format and how to request current versus historical data.

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 single required parameter is named 'input' with no schema description and no type information. The description hints that a 'past moment' can be requested but does not explain how to specify that moment or what the input should contain.

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 identifies a clear resource and scope: AIS-reporting ships around Finland, with current or historical timing. However, it does not explicitly state the action (retrieve/query) and does not differentiate this tool from sibling cell_sensor_ais_fi.

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?

It mentions that the tool can be used 'now, or at a past moment,' which implies temporal usage, but it gives no guidance on when to choose this tool over cell_sensor_ais_fi or other sensor tools. There are also no prerequisites or exclusions.

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