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

Annotations already cover the safety profile (readOnly, idempotent, open-world, non-destructive), so the bar is lower, and the description still adds real context: the 'unscored' handling of missing scores, the unit conventions (ft, kt, s, F, mi), that directions are FROM, and that source/freshness metadata comes back. These are behavioral traits not present in the annotations or schema.

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, front-loaded sentences with no filler; purpose leads and units/metadata follow. The telegraphic units sentence is dense but each line carries information an agent can act on.

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?

Safety is covered by annotations and, with no output schema, the description at least sketches the return shape (reasons, vetoes, metadata). But a nested three-property query with 0% schema coverage and a required spot identifier is only partially served; spot syntax and the activity enum are left to the schema and description alike.

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%, so the description must compensate. 'Hourly' hints at the hours parameter and 'activity scores' hints at the activity parameter, but the required spot parameter's format is never explained and the schema's hours default/range and the 13-value activity enum go unmentioned, leaving meaningful gaps.

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 resource and output: hourly published activity suitability scores with reasons and vetoes. An agent can tell it produces derived activity-suitability judgments rather than raw conditions, which distinguishes it from raw-metric siblings like get_wind or get_waves. However, it never names or contrasts a sibling (e.g. get_conditions, compare_spots, get_surf_forecast), so differentiation is implicit.

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?

No when-to-use guidance, prerequisites, or alternatives are given. The only conditional statement ('Missing activity scores are unscored') explains an output edge case, not how to choose this tool over get_conditions or get_forecast.

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