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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, but the description adds important context beyond them: it is a live NOAA proxy, nothing is stored, no API key is required, it returns the latest NWS gridpoint forecast, and an unknown location key or NOAA outage yields a source-unavailable error.

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 front-loaded with what the tool returns and how it differs from siblings, followed by concise behavioral and error notes. The density is appropriate for the amount of useful information, and no sentence is redundant.

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, the description compensates by naming the returned forecast fields: temperature, wind speed and direction, short and detailed forecast text, and day/night periods. It also covers source freshness and failure behavior, leaving nothing critical for an agent to infer before calling it.

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?

There is only one parameter and schema description coverage is 100%, so the schema already documents the location key, accepted values, and default. The description does not add additional syntax or selection guidance beyond the schema, which is acceptable at the baseline for fully covered parameters.

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 states a specific verb and resource: a NOAA forecast for an agricultural region, covering the next several day/night periods with named fields. It clearly distinguishes itself from get_weather and get_weather_history, so an agent can select it without opening sibling schemas.

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 explicitly says to use this tool for the outlook ahead, then names the alternatives get_weather for current observed conditions and get_weather_history for recent past weather. This is exactly the when-to-use versus when-not-to-use guidance an agent needs.

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