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

Beyond the readOnlyHint annotation, the description discloses the data source (USGS FDSN), update frequency (hourly), historical depth (to 1960), and the rolling 7-day calculation window. It also clarifies the scope ('global') and names the return fields, providing rich behavioral context.

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 description is two sentences and front-loaded with the core function and key details. The formula is dense but directly explains the metric, and the usage guidance is compact. No redundant or vague language.

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?

Despite no output schema, the description names the three return fields and their semantics. It includes usage scenarios, update frequency, data source, and history availability. The optional parameter behavior is covered by the schema, so all necessary selection context is present.

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% for the single optional 'days' parameter, which is already well-described (history series, max 5 years, Gold tier requirement). The description adds no additional parameter information, so it does not exceed the schema baseline.

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 clearly states the tool returns a 0-100 global seismic energy-release intensity score, listing the exact output fields (intensity_score, max_magnitude_7d, m4plus_count) and the technical basis. It identifies a distinct resource (seismic/earthquake activity) that separates it from the many sibling tools.

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 provides explicit when-to-use scenarios: 'Call when the user asks about earthquakes, seismic activity, quake clusters, magnitudes, or geophysical hazard, or when timing catastrophe-risk triage, insured-exposure loss estimates, or severity-based alerts.' It does not mention when not to use it or suggest alternative tools, but the guidance is clear and actionable.

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