maritime_coverage

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

With no annotations, the description still carries useful behavioral context: the output is always returned whole and is never trimmed, and a zero cell means no feed coverage rather than empty sea. It does not disclose freshness, source mix, or rate-limit behavior, but the misinterpretation guard is genuinely valuable.

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?

Four tight sentences ordered from purpose to grid geometry to the zero-cell caveat to the 'returned whole' note, with no filler. The grid-coordinate sentence is dense but earns its place.

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?

An output schema exists, so full return-value documentation is not required. The description still covers shape, resolution, indexing, and null-cell meaning. The one real gap is that max_age_s has no explanation, though it is optional and has a default.

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% and the single parameter max_age_s is never mentioned, so its unit, effect on the 'live' counts, and the consequence of raising or lowering it are all undocumented. With one param and no compensating description, this falls below the 3 baseline.

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 concrete verb and resource: a 36x72 grid of live-vessel AIS counts at 5-degree resolution, and it also gives the exact row/column orientation. An agent can distinguish it from single-point tools like query_vessels or maritime_vessels_bbox, though it does not explicitly call out a sibling by name.

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 intended use, understanding where keyless AIS coverage exists, can be inferred from the phrase 'Where keyless AIS actually reaches'. The description never says when to pick this tool over maritime_chokepoints, maritime_pipeline_stats, or vessel queries, and it offers no exclusions.

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