check_tax_number

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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds that the tool returns company name and address if valid, which is useful context. However, it does not disclose behavior for invalid tax numbers, error handling, or any rate limits. With annotations covering safety, the description provides moderate added value.

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 two sentences (16 words in Hungarian) with no unnecessary words. Every sentence conveys essential information: what the tool does and what it returns. It is front-loaded and efficient.

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?

The tool has one parameter and no output schema. The description explains the return (company name and address if valid) but omits what happens when the tax number is invalid (e.g., error message, null response). This missing detail makes it slightly incomplete for an agent to fully anticipate behavior.

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 schema covers the single parameter 'tax_number' with 100% descriptive coverage, including format and example. The description does not add any new information about the parameter beyond what the schema provides, 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 the tool checks a tax number in the NAV system and returns company name and address if valid. This specific verb-resource pair distinguishes it from sibling tools, which are primarily for document, partner, and bank account management.

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 (when you need to validate a tax number) but provides no explicit guidance on when to use this tool versus alternatives, nor does it mention prerequisites or exclusions. The distinct purpose from siblings partially compensates.

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