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

Annotations already indicate readOnlyHint=true, destructiveHint=false, idempotentHint=true, openWorldHint=true, so the safety profile is clear. The description adds the update frequency ('updated every minute (USGS)'), which provides useful context beyond annotations, but does not disclose other behavioral details like pagination or rate limits. Acceptable given annotation coverage.

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 a single sentence that efficiently conveys the tool's purpose, parameters, and update frequency. No redundant information: every word is necessary. Ideal conciseness.

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?

Given the presence of an output schema (context indicates 'Has output schema: true'), the description appropriately does not detail return values. It covers purpose, parameters, and update frequency. One minor gap: it does not explicitly state that the feed returns a list of events, but the output schema likely handles that. Overall complete for a simple feed 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?

The input schema has 100% description coverage, with both parameters having clear descriptions and enums. The description merely restates the parameter options (magnitude thresholds and time windows) without adding new meaning or usage patterns. Baseline score of 3 is appropriate when schema does the heavy lifting.

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 purpose: get real-time earthquake feed filtered by magnitude threshold and time window. It specifies the verb 'Get', the resource 'real-time earthquake feed', the key parameters, and the data source (USGS). This distinguishes it from sibling tools like earthquake.events.count and earthquake.events.search.

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 implies usage context by listing the parameter options (magnitude thresholds and time windows), but does not explicitly state when to use this tool versus alternatives like earthquake.events.search or earthquake.events.count. No guidance on when not to use it or which alternative to choose.

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