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

Annotations already cover readOnly, idempotent, openWorld, and non-destructive hints, so the bar is lower. The description adds genuinely non-structured behavioral context: the cost model (free within a daily allowance, then $0.002 USDC per call via x402) and the 'in force' filter meaning only currently active alerts are returned, which is meaningful for an open-world read.

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 short sentences with the core capability front-loaded and zero padding. The pricing sentence consumes roughly half the description, which is justified for a paid x402 endpoint but is slightly disproportionate to the functional payload.

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?

An output schema exists, so return values need not be explained, and annotations carry the safety profile. Coverage is close to complete for a 3-parameter geo query, though it omits geographic coverage limits (UK only) and how results distinguish alerts from warnings or rank by distance.

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 description coverage is 100%, so lat, long, and dist with its default of 5 are fully documented in the schema itself. The description only restates the geospatial model ('radius of a point') without adding unit conventions, coordinate format, or radius bounds, so the baseline of 3 applies.

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 resource ('Flood alerts and warnings in force') and a spatial scope ('within a radius of a point'), which implicitly separates it from the unfiltered sibling uk-flood__warnings. It does not explicitly name a sibling or call out the severe-only variant, so it falls short of a 5.

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?

No when-to-use or when-not-to-use guidance is provided. An agent must infer from the phrase 'near a point' that this is the right tool when it has coordinates, and there is no direction on how it differs from uk-flood__warnings, uk-flood__severe-warnings, or uk-flood__flood-areas-near.

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