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 real contribution is the billing behavior: free within the daily allowance, then $0.002 USDC per call via x402. That cost/throttling context is genuinely beyond the structured fields and useful for an agent deciding whether to call. It does not disclose alert freshness or coverage gaps.

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?

Two tight sentences, purpose front-loaded, and the pricing sentence earns its place by surfacing a call-cost constraint an agent would otherwise not see.

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 an output schema present, return values need no explanation, and one required parameter with full schema coverage keeps the surface small. The definition is adequate; it stops short of noting the relationship to us-weather__alerts-point or what kinds of alerts/severities are returned.

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%, so baseline would be 3, but the description adds meaning the schema lacks: the schema only says 'State code, e.g. CA' while the description clarifies the parameter also accepts marine areas. That extra scope information is a real increment over structured data.

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 verb+resource ('Weather alerts in force') and scopes it to 'a US state or marine area', which implicitly separates it from the point-based sibling us-weather__alerts-point. It never names that sibling explicitly, so an agent must infer the routing from the 'state or marine area' phrasing.

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?

Usage is only implied: the 'for a US state or marine area' scope suggests this is the area-level alert tool, versus the point-level sibling. There is no explicit when-to-use/when-not statement and no prerequisites (e.g. whether an area code must come from us-weather__points).

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