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

Annotations already establish readOnlyHint and openWorldHint, so safety is covered. The description adds useful framing about what the payload is (forecaster narrative covering mechanisms and uncertainty, rather than raw numbers), but says nothing about cadence/freshness (AFDs are periodic), text length, or availability for a given point.

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?

A single dense sentence front-loads the source (NWS forecaster) before the artifact and its contents, with no filler. The trailing colon list adds information rather than padding, though the wording is slightly compressed for the amount of concept it carries.

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 must convey what comes back; it identifies the AFD and hints at its contents, which is the right instinct. It still leaves the return shape underspecified (free text vs. structured sections, one discussion vs. several, how stale it may be), which matters for a no-output-schema 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 100% and each parameter already carries its own description, including the AK/HI latitude range and the city-roster fallback, so the schema does the heavy lifting. The description's 'US location' phrasing only loosely echoes those constraints without adding syntax or precedence rules beyond what the schema states.

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 names a specific artifact (the NWS Area Forecast Discussion) and its scope (the office covering the queried point), which is far more precise than the name alone. It implies a clean contrast with the numeric sibling `forecast`, but never names or explicitly differentiates itself from `what_changed`, `whats_unusual`, or the other siblings.

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?

Geography is the only stated condition ('for a US location', reinforced by 'use lat/lon for anywhere else' in the schema). There is no explicit guidance on when an agent should reach for the reasoning discussion versus the plain `forecast` or the anomaly/history siblings, so the routing decision is left to inference.

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