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

Annotations declare readOnlyHint and openWorldHint, and the description adds two things beyond that: the validation logic used (checksum and date logic) and the explicit statement 'No application-level storage', which reassures about data handling. It also notes the return of normalised forms and error codes, though it does not enumerate error codes or failure behaviour.

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 dense, front-loaded sentences: the first carries purpose and scope, the second carries behaviour and the storage disclaimer. Every clause earns its place, including the orgnr sub-forms, which map to the enum.

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 correctly compensates by stating it returns normalised forms and error codes. It stops short of describing the response shape or how invalid input is signalled, but for a stateless read-only validator this is close to 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?

Schema description coverage is 100% with a documented enum for 'type', so the baseline is 3. The description lists the identifier types but adds only marginal semantics beyond the enum values, with the useful exception of expanding orgnr to include sole-trader and VAT forms — which is not visible in the schema.

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?

States a specific verb (validates) and resource (Swedish identifiers) and enumerates exactly which identifier families are covered (personnummer, samordningsnummer, orgnr, bankgiro, plusgiro, OCR). This clearly separates it from siblings like iban_check or email_check, which handle non-Swedish/non-identifier domains.

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?

Usage is implied by the identifier list — an agent can infer it should call this for Swedish ID validation. However, there is no explicit when-to-use/when-not guidance and no alternatives named (e.g. iban_check for IBANs, se_account_to_iban for account conversion).

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