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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the description's job is to add context. It does: the ~45-day retention ceiling, buoy vs partner reporting intervals, and the NOAA NDBC origin. It stops short of describing row contents or pagination behaviour on multi-thousand-row pulls.

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?

Front-loaded with the core definition, then scope, then usage, then provenance—no filler sentences. Slightly denser than necessary with three separate parenthetical clauses, but every clause carries information.

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?

No output schema exists, so the description carries the return-value burden; it characterises rows as 'standard meteorological rows' and gives example measures, which is enough for an agent to select it, though column names and units remain unspecified.

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 100%, so hours, limit and station_id are already documented with defaults and maxima. The description's '~45 days' does loosely map to the hours max of 1080, but it adds no syntax, unit, or filtering nuance beyond the schema 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?

States a specific resource and scope: a recent observation time series for one NDBC station, with the retained window (~45 days) and typical reporting cadence. It implicitly separates itself from ndbc_latest_obs and ndbc_stations through 'time series' and 'one station', but never names those siblings, so the differentiation is left to inference.

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?

Explicitly frames the tool as trend-oriented ('Use for trends') and supplies two concrete scenarios (wave height change this week, wind event on the 3rd). It gives clear positive context but no exclusions or named alternatives for point-in-time queries, which would belong to ndbc_latest_obs.

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