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

Annotations already declare readOnlyHint=true, so the description adds value by stating 'without returning the events themselves' and positioning the tool for sizing queries. This clarifies the tool's read-only, summary nature beyond what annotations alone provide.

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 sentences, each earning its place: first states the action, second provides usage context. No filler, front-loaded with the core purpose.

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?

The description covers the action and usage context but does not specify the return format (e.g., returns a number). Since no output schema exists, this omission leaves the agent guessing what the output looks like. Adequate but not complete.

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?

Input schema coverage is 100%, with all 15 parameters having descriptions. The description adds no additional parameter-level information beyond 'matching the given search parameters.' Baseline of 3 is appropriate.

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 verb 'Count' and the resource 'earthquakes', and specifies that it does not return events, distinguishing it from sibling tool 'find-earthquakes' which likely returns events. This makes the purpose unmistakable.

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 guidance: 'Useful for sizing a query before running it.' This implies the tool should be used before a search query to gauge result size, and contrasts with sibling tools that return data. However, it doesn't explicitly state when not to use it or name alternatives directly.

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

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

Annotations already mark readOnlyHint=true and openWorldHint=true, so the description doesn't need to emphasize safe read behavior. It adds that the tool returns 'origin quality metrics', a useful detail beyond annotations, but does not mention pagination, response size, or whether all fields are always present.

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, clear sentence with an example inline. Every word is meaningful and there is no filler. Highly front-loaded: key action and parameter type stated immediately.

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 tool has only 1 parameter, full schema coverage, and informative annotations, the description is nearly complete for a lookup tool. It could mention whether the response is synchronous or if the ID format is always lowercase, but overall it is largely sufficient.

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%; the schema already defines eventid as a string with a description. The description adds a concrete example ('us6000d3zh') which aids understanding, but doesn't add deeper semantics beyond what the schema provides. Baseline 3 is appropriate.

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 gets detailed information for a single earthquake using a specific USGS event ID. The verb 'Get' and resource 'detailed information' are specific, and the example helps differentiate from sibling tools like find-earthquakes which likely return lists.

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 use when you have a specific event ID, but it does not explicitly state when not to use it or contrast with count-earthquakes. The sibling tools exist but no direct guidance on trade-offs is given.

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

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

Annotations already declare readOnlyHint=true (safe read) and openWorldHint=true (data may change). The description adds that it returns a 'summary' (concise, not full detail) and confirms parameters are filters. Bar is lower due to annotations; description adds small value but doesn't explain things like rate limits, pagination, or whether results are sorted by default (the schema says orderby defaults to 'time').

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?

Short single sentence that is front-loaded with the key action ('Search the USGS earthquake catalog...'). No filler or redundancy. Could be slightly improved by noting the return type, but overall concise.

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 high complexity (15 params, no output schema, rectangle/circle interaction), the description is incomplete. It does not explain return format or behavior beyond 'summary', nor does it document the rectangle-circle intersection behavior visible in the schema. The annotations add value but the description should compensate more for the missing output schema. A 3 reflects this gap.

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 schema already has 100% description coverage with detailed explanations for all 15 parameters (e.g., ISO8601 format for time, units for depth/radius, circular vs rectangle logic). The description adds minimal meaning beyond 'earthquake catalog' context. Baseline 3 is appropriate.

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 searches the USGS earthquake catalog by specific criteria (time, location, magnitude, depth) and returns a summary. It distinguishes from siblings like 'find-earthquake-details' (which likely returns full details) and 'count-earthquakes'. However, it could more explicitly contrast with these siblings.

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 use for searching earthquakes with given filters but provides no guidance on when to prefer this over 'find-earthquake-details' or 'count-earthquakes'. It does not mention when not to use it, e.g., for detailed event info or aggregation queries.

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