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

The annotations already declare a safe, idempotent, closed-world read, so the description need not argue safety. It does add genuine value by disclosing that results are sorted by distance and that the dataset is curated, but it omits what happens with a call containing no filters and how town and lat/lng interact when both are supplied.

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, both dense with information, with the return shape stated first and the two search strategies second. There is no filler, no restatement of the tool name, and nothing that could be cut without losing meaning.

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?

There is no output schema, so the description's field list is helpful, and it covers both spatial entry points. But for a 7-parameter tool with zero required parameters, it leaves the agent guessing what an unfiltered call returns and whether town and lat/lng are mutually exclusive or combined.

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 only 29%, so the description carries real weight, and it does clarify that town is a slug and that radius_km pairs specifically with lat/lng. However, the limit, type, level, and lat/lng parameters get no added meaning, and the implicit beardown of 7 parameters leaves several semantics documented only by their names.

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 pairs a specific verb with a specific resource and enumerates the payload ('exact coordinates, break type, direction and level'), so an agent immediately knows what comes back. It does not distinguish itself from the sibling surf_pools, which is a real ambiguity because 'pool' is also a value of its own type enum.

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?

It gives clear usage modes — a town slug search versus a lat/lng plus radius_km search — which tells the agent how to drive the tool. It never states when to prefer this tool over surf_pools, surf_cams, or surf_forecast, nor does it set any exclusions, so tool-selection guidance is only implied.

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