USE THIS to verify a Swedish personnummer (personal identity number) before relying on it — never assume the digits are valid. Accepts the 10- or 12-digit form and checks the Luhn check digit. Validates structure only; does NOT confirm the number is registered.
| Name | Required | Description | Default |
|---|---|---|---|
| personnummer | Yes | The Swedish personnummer (10 or 12 digits; +/-/spaces ignored). |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Discloses limitations (validates structure only, no registration check) and aligns with readOnlyHint annotation. No contradictions; provides useful behavioral context beyond annotations.
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?
Three front-loaded sentences with no wasted words. Imperative tone, key details in order: purpose, usage, limitation.
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?
Adequate for a simple validation tool with one parameter and no output schema. Covers what it does, format, and limitation. Could mention return type but not critical.
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 has 100% coverage with parameter description already clear. Description adds minor extra context about accepted digit forms and Luhn check, but does not significantly enhance understanding beyond 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?
Clearly states the tool validates a Swedish personnummer before relying on it, specifies it checks Luhn digit, and distinguishes from sibling validation tools by naming the specific country identifier.
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?
Explicitly advises to use before relying on a number, and clarifies it does not confirm registration. However, it does not name alternative tools for registration checks or specify when not to use.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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