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

Beyond the readOnlyHint and idempotentHint annotations, the description discloses that the user is not signed in, the server will respond with an authentication challenge, and the client should prompt account connection. It also instructs agents not to fabricate an answer, which is crucial behavioral guidance.

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 three sentences: purpose, requirement/auth state, and instruction. Every sentence earns its place, with front-loaded function and no filler. It is concise but information-dense.

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 zero-parameter read-only tool, the description covers function, auth prerequisites, current auth state, and expected failure behavior. It does not describe the return shape, but the output is implied as state-level risk aggregation. Slightly more detail on the response format could make it fully 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?

With zero parameters in the schema, the description carries no parameter burden. The baseline score of 4 applies, and the description appropriately implies a simple zero-parameter aggregation request.

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 opens with 'Aggregate skimmer risk by US state', a specific verb and resource that clearly defines the tool's function. This differentiates it from sibling tools like route_risk or location_devices by geography and aggregation level. The 'Data Licensee tier' qualifier adds useful context.

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 explicitly states when to call the tool (when the user asks for their own business, reseller, or licensed data) and explains the auth challenge behavior. It does not name alternative sibling tools for other use cases, so it lacks full when-not guidance, but it 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.