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

With no annotations, the description carries the full burden. It usefully discloses that the tool reports evidence grades, board availability, and the result of checking ports without boards — which implies this is an aggregate audit rather than a data-returning query. However, it does not say whether the operation is read-only, whether a country filter narrows aggregates or returns rows, or how large the response is.

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?

Two sentences, no filler, with the resource scope front-loaded and the usage instruction second. The phrase "what happened when we checked those that do not" is slightly oblique but still earns its place by describing the probe-outcome dimension.

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?

No output schema and no annotations, so the description must convey what comes back — and it does so in terms of the three coverage dimensions. The remaining gap is the interaction between the optional country filter and the reported aggregates, which an agent would need to know before calling.

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% and both parameters are optional, so the schema already documents `query` as an alias for `country` and the ISO-2/name filter. The description adds nothing about parameters at all — notably it never clarifies that filtering by country changes the scope of the ledger. Baseline 3 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?

The description states a specific resource (a coverage ledger over 2,951 ports) and enumerates its contents: counts by evidence grade, counts of machine-readable movement boards, and probe outcomes for the rest. That is concrete enough to distinguish it from per-port siblings like shipping_port or shipping_port_calls, though it never names an alternative explicitly.

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?

"Call this to find out what this service does NOT know about ports before relying on what it does" gives a clear triggering condition: assess coverage gaps prior to trusting port data. It lacks an explicit when-not or a named alternative (e.g. shipping_freshness, shipping_status), so it stops short of full routing guidance.

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