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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered; the description adds genuinely non-obvious behavior — that no charge applies if the address cannot be found, and that the call costs $0.02 via x402/USDC on Base. It stops short of describing error behavior when inputs are ambiguous or what the response payload looks like.

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 capability statement is front-loaded, followed by usage triggers, then billing caveats — a sensible order with little waste. The first sentence is long and piles several output types together, 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?

With no output schema, the description does the work of naming what comes back (overall risk and drivers, flood zone, per-peril ratings, disaster history). Combined with pricing and non-billing-on-miss behavior, an agent has enough to call it correctly; only the lat/lon contract and any precision/coverage limits remain thin.

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?

Only the 'address' parameter is documented in the schema (33% coverage), so the description partially compensates by signalling two input modes: 'a US address or coordinates'. It does not explain how lat and lon relate, whether they must be supplied as a pair, or what happens if both an address and coordinates are given, leaving the 0-required-parameter contract ambiguous.

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 opens with a specific verb+resource — 'One-call natural hazard report for a US address or coordinates' — and enumerates the concrete outputs (FEMA flood zone, flood-insurance requirement, per-peril ratings, county disaster history). This is unmistakably distinct from the copyright- and sanctions-oriented 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?

It gives explicit triggering contexts: 'Use when evaluating, listing, insuring or financing a property, or when asked about flood zones or natural hazard risk at an address.' That covers when to reach for it, but names no alternatives or exclusions, so a 4 rather than a 5.

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