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

With no annotations, the description carries the burden. It usefully notes that the tool returns the same operational signal as get_port_risk for each port and that the result supports ranking congestion, delay, and demurrage exposure. However, it does not disclose data freshness, rate limits, failure behavior for invalid port codes, or whether partial results are returned if one port fails.

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 front-loaded with the core purpose, immediately followed by when-to-use guidance, then the parameter details with an example. Every sentence earns its place and the format is scannable.

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?

For a single-parameter tool with an output schema available, the description is complete enough for correct selection and invocation. It explains the purpose, the use case, the parameter format, and the relationship to the singular sibling tool.

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 0%, so the description must compensate for the parameter. It does so by specifying that port_ids is a list of UN/LOCODEs and giving concrete examples like ['BRSSZ', 'BRPNG', 'CNSHA']. This adds format and usage meaning beyond the bare array-of-strings schema.

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: 'Compare CURRENT congestion across several seaports in a single call.' It explicitly differentiates from the singular get_port_risk and the trend-focused sibling by emphasizing multi-port comparison and current congestion signal.

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?

Clear usage context is provided: use when choosing between ports for routing, scheduling, port selection, or portfolio scanning. It names the singular get_port_risk as the comparative baseline, but does not explicitly mention when to prefer get_port_trend or list_supported_ports.

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