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

Annotations already cover the safety profile (readOnly, idempotent, openWorld, non-destructive), yet the description still adds real behavioral context: source sample dates and unavailable states must be preserved, and satellite clarity is explicitly a relative index rather than measured dive visibility. It also discloses that source/freshness metadata is returned, which is not visible in any structured field.

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 purpose, then caveats, then units and return shape. The units/directions line is terse but dense with useful convention information; little is wasted.

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 and 0% parameter coverage, the description does the minimum-plus: it hints at return contents (data plus source/freshness metadata) and flags unit conventions. However it never describes the risk scale or categories, what an unavailable state looks like, or how an unverified spot is handled, leaving meaningful gaps for a domain-specific hazard tool.

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% for the single nested 'spot' parameter, so the description carries the burden. 'Verified spot' adds a meaningful constraint not present in the schema (which only shows a regex and length limits), but it never explains the expected spot identifier format or how verification status is determined. Partial compensation only.

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 verb-equivalent ('Rip current risk for a verified spot'), which is clearly distinct from siblings like get_waves, get_currents, or get_surf_forecast. It does not explicitly name a sibling to route against, but the resource is 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?

There is no when-to-use guidance, no statement of when another tool (e.g. get_surf_forecast or get_hazards) is preferable, and no explanation of what makes a spot 'verified' or what to do if it is not. The agent must infer the usage context entirely.

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