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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint, so the safety profile is covered. The description does add genuinely new behavior — the metered pricing (free within daily allowance, then $0.002 USDC per call) and the 'currently in force' active-only filter — but says nothing about freshness or update cadence.

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 scope statement front-loaded and the cost note last; every sentence carries information. The only cost is the conflation of severe and non-severe warnings in the opening clause.

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 annotations cover the read-only profile. The description supplies scope and pricing, leaving only the sibling-differentiation gap relative to uk-flood__warnings.

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?

The tool takes no parameters, so there is nothing for the description to disambiguate; baseline 4 applies. No syntax or format detail is needed or missing.

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?

It names the resource (flood warnings currently in force) but supplies no verb, leaving it ambiguous whether the tool lists, searches or fetches. The scope sentence is also muddled: the tool is named 'severe-warnings' yet claims to return both severe and ordinary flood warnings, which blurs its boundary against the sibling uk-flood__warnings.

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 guidance is given on when to choose this over uk-flood__warnings or uk-flood__warnings-near, nor any precondition. The agent must infer the distinction from the name alone.

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