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

With no annotations, the description carries the full behavioral burden. It usefully discloses that this is a PRO tool and caps ZIPs at 25, but it omits whether the operation is read-only, what permissions are required beyond the token, and what the response includes.

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 front-loaded sentence with no filler, and the key operational limits appear early. It is concise, though its brevity contributes to the missing usage and parameter context.

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?

For a tool with no annotations, no output schema, and only 25% schema parameter coverage, the description is too sparse. It does not explain return values, usage relative to siblings, or enough parameter detail for correct invocation.

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 description coverage is only 25%, so the description needs to compensate. It clarifies that days is a lookback window and that zips is capped at 25, but it leaves min_mag and the expected ZIP string format unexplained.

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 states the resource and scope reasonably well: recent earthquakes near up to 25 ZIPs, aimed at facilities, insured properties, and data centres. However, the tool name 'sites_check' is vague, and the description does not distinguish this tool from siblings like recent_quakes or seismic_history.

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?

There is no explicit guidance on when to use this tool versus recent_quakes or seismic_history. The use case is implied by 'facilities, insured properties, data centres', but there are no exclusions, alternatives, or prerequisites stated.

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