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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower, and the description still adds value: it clarifies the tool does not refresh facility details or compute live bridge clearance, and that results carry source/freshness metadata. The unit conventions further characterize the output.

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?

Three short sentences, front-loaded with the core action and followed by scope exclusions and unit/output notes. Every sentence carries information, though the units clause is terse enough to feel slightly cryptic.

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, the description usefully signals that a data payload plus source/freshness metadata is returned, and it bounds scope with the two negative statements. Missing detail on identifier sourcing and result shape keeps it just short of full completeness.

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 coverage is 0% and the single parameter is a nested object with only min/max length on 'id'. The description compensates partially by stressing 'exact ID', but gives no format, example, or source for the identifier, leaving the semantics thin.

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 (look up) and resource (published coastal POI) plus the key constraint 'by its exact ID', which distinguishes it from the search_pois / find_* siblings. It doesn't name the sibling explicitly, but the exact-ID requirement makes the intent unambiguous.

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?

'by its exact ID' implies you must already have an identifier, and the negative clauses ('does not refresh facility details or calculate live bridge clearance') sketch when-not to use it. However, no positive routing to the obvious alternative (search_pois) or guidance on where to obtain an ID is given, so usage is only implied.

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