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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and non-destructive behavior, so the safety profile is covered. The description adds meaningful behavioral context beyond annotations: it returns dated signals, covers specific external sources, and explicitly refuses to issue a trust verdict. It does not describe failure modes or freshness mechanics, but the added context is substantial.

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 definition is two sentences, front-loads the resource and scope, and then lists the signals in a compact way. Every clause earns its place: scope, signal categories, and the no-verdict constraint are all relevant.

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?

With no output schema, the description appropriately explains what the tool returns by enumerating the signal categories. Annotations already carry the safety profile, and the only parameter is fully documented in the schema. For a read-only, open-world lookup tool, the description is complete enough 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 100%, and the single 'name' parameter is already documented in the schema as a store name, domain, or URL. The description does not add further parameter semantics beyond what the schema provides. A baseline score of 3 is appropriate when the schema fully covers the parameter.

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 identifies the resource and scope: it returns dated signals about an online store selling in Uruguay or for foreign purchases. It lists the specific signal categories, so the agent knows what the tool does. It does not explicitly distinguish itself from siblings, but no sibling appears directly overlapping.

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 gives clear usage context: stores selling in Uruguay or foreign-purchase cases. It also sets an important behavioral boundary, 'Nunca da un veredicto de confianza', and instructs the agent to present signals and let the person decide. It does not name alternative tools, but the guidance is otherwise specific.

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