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

Annotations already declare readOnly, idempotent, and non-destructive. The description adds valuable behavioral context beyond annotations: IBANs are returned masked, API key is required, and the operation consumes no credits. This goes beyond what structured annotations 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?

The description is concise (three short sentences in Italian) and front-loaded with the core purpose, then key details like masked IBANs and authentication/cost. Every sentence carries useful information without fluff.

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 simple list tool with one optional parameter and no output schema, the description covers purpose, return content (VIES status, IBAN counts), masking, and auth. It lacks pagination or response structure details, but these are not critical given the simplicity and good annotations.

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 only parameter 'only_alerting' is fully described in the input schema (100% coverage), including its behavior and conditional filtering. The tool description adds no extra parameter meaning, so 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 'Elenca i fornitori che questo account sta sorvegliando' (lists monitored suppliers), a specific verb and resource. It further distinguishes from siblings by specifying aggregated VIES status and IBAN confirmation counts, making it an overview rather than a single-supplier tool.

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 (overview of all monitored suppliers) and provides prerequisite/cost info (API key, free credits), but does not explicitly reference alternatives like guardian_supplier_status or state when not to use it. Sibling differentiation is only implicit.

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