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

Annotations already establish read-only, idempotent, open-world and non-destructive behavior, so the bar is lower; the description still adds real context beyond them: the upstream source (USGS FDSN, official, real-time, no key required), the paid-call model (x402 0.03 USDC on Base), and the default magnitude threshold M>=4.5. It stops short of describing latency, refresh cadence, or what happens when no events match.

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 core purpose and detection rule are front-loaded and dense but readable. However, the x402 price is stated twice ('$0.03 USDC x402 Base' and '[x402: 0.03 USDC per call on Base]'), which is pure redundancy in an otherwise single-sentence body.

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?

There is no output schema, so the description carries the return-value burden and does a fair job by naming the alert level, tsunami flag, and cluster detection output. It leaves the response shape (fields, units, event list structure) unspecified, which is a modest gap for a no-param, no-output-schema data 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 reported at 100%, so baseline is 3, but that coverage is a single generic 'product parameters (JSON or text)' string. The description adds only that the magnitude floor is 'tunable' with a default of M>=4.5, without naming the parameter, its format, or the other tunable knobs, so it does not meaningfully compensate for the vague schema.

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 ('latest earthquakes') plus the distinctive derived outputs (PAGER alert level, tsunami flag, active seismic cluster detection with an explicit >=3 events/24h rule). This is clearly distinguishable from every sibling tool such as air_quality, space_weather_risk, or gdelt_tension.

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?

The description frames the use case ('the actionable signal for insurance-risk and disaster prediction markets'), which implies context, but never states when to prefer this tool over alternatives or any exclusion conditions. Usage must be inferred from the domain framing rather than read directly.

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