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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds that validation is checksum-based and gives the endpoint, but says nothing about the return shape (valid flag, normalization, per-scheme error detail) or the meaning of the 'AUTO' type.

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 compact elements: a front-loaded purpose sentence and the endpoint annotation. No filler, and the highest-value information (what is validated) comes first.

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 2-parameter, fully schema-documented validator with annotations covering side effects, the description supplies enough to call it correctly. The only real omission is what the response contains, which is minor here but not zero since no output schema exists.

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%, so both parameters are already documented in the schema, setting the baseline at 3. The description's scheme list gives useful context for what 'type' selects, but it does not explain the 'AUTO' value that the schema itself uses as its only example.

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 uses a specific verb ('Validate') plus an explicit enumeration of the identifier schemes covered (LEI, EORI, SIREN/SIRET, Steuer-ID, Codice Fiscale, NIF/CIF, NIP, BSN, CRN, EIN). An agent can tell this is a checksum/format validation tool for European corporate and national IDs. It stops short of naming a sibling it is distinct from, so it lands at 4 rather than 5.

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 enumerated identifier types imply when the tool applies, but there is no explicit when-to-use, when-not-to-use, or alternative routing (e.g. to tinplate_eu_vat_iban for IBANs or tinplate_sanctions_screener for screening). Usage is inferable from the subject matter alone.

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