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

No annotations are provided, so the description carries the full burden. It discloses key behavioral traits: no auth required, free, and the calibration status of returned data ('decision-grade signals'). However, it does not state rate limits, pagination behavior, or whether the feed is eventually consistent. For a read-only public feed, these are minor gaps, but the description does an above-average job of conveying the tool's operational profile.

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 most critical information (free, no auth, live feed) in the first sentence. It then efficiently layers the recommendation, the returned data types, and the return schema. Every sentence earns its place with no redundancy.

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?

Despite having an output schema, the description explicitly enumerates the returned fields (p50/p90 wait times, demurrage exposure, confidence intervals, calibration status) and provides a concrete return example. Combined with the clear usage guidance, this gives an agent everything needed to invoke the tool correctly. No annotations are present, but the description compensates fully.

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 tool takes zero parameters, so the baseline is 4. The description appropriately does not discuss parameters and instead focuses on return values and usage context. No penalty applies.

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?

States a specific verb (Get) and resource (live public port-delay feed) with explicit scope ('all covered ports'). It further distinguishes itself by declaring it is the recommended 'FIRST CALL' and contrasts with 'paid or trial-gated tools'. An agent can immediately tell this apart from siblings like get_port_congestion_risk or get_port_operations_status.

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?

Explicitly states when to use this tool ('recommended FIRST CALL for any agent exploring Aether-X', 'to discover which ports have decision-grade signals before calling paid or trial-gated tools'). It names the alternative category (paid/trial-gated tools) and the condition that selects them, leaving nothing to inference.

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