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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint. The description adds valuable context: relative sea level combines ocean rise and land movement, trends vary by region, and a long water-level record is needed. No contradictions with annotations.

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?

The description is three concise sentences, each serving a purpose: stating what the tool returns, explaining relative sea level, and giving usage conditions. No unnecessary words.

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?

Despite no output schema, the description mentions key fields (trendUnits, startDate/endDate) and covers the tool's behavior sufficiently. With rich annotations and all parameters optional, it provides complete context for effective use.

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 100% with descriptions. The description adds value by explaining the station parameter format (e.g., '9414290' for water-level stations) and clarifying the affil parameter's role. It also explains the response_format options in plain language.

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 explicitly states it gets long-term relative sea level trends at a NOAA station, including trend, error, period, and seasonal amplitude. It distinguishes from siblings by explaining the concept of relative sea level and noting the requirement for a long record, differentiating it from other NOAA tools like water levels or extreme events.

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?

The description provides clear guidance on when to use: for long-term trends, and mentions omitting station to list all. It also points to sibling tools (noaa_search_stations, noaa_find_nearest_stations) for finding stations, but does not explicitly state when not to use this tool.

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