validate_bg_egn

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

With no annotations, the description carries full burden. It clearly states it 'Validates structure only,' disclosing that it does not check actual issuance or validity beyond format. This is transparent for a validation tool.

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 sentences with no filler. Every word contributes meaning. Front-loaded with the key instruction 'USE THIS'.

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 1-parameter tool with no output schema, the description adequately covers what the tool does and its limitations. No missing information for typical usage.

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 already describes the parameter ('10-digit Bulgarian EGN (spaces ignored)'), and description coverage is 100%. The tool description adds the validation method (mod-11 check digit), which provides some added context beyond 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?

The description explicitly states the tool's purpose: verify a Bulgarian EGN. It details what it checks (10-digit form, weighted mod-11 check digit) and clearly distinguishes from sibling validation tools by specifying the country and type.

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 starts with 'USE THIS to verify a Bulgarian EGN before relying on it,' providing clear when-to-use guidance. It does not explicitly mention when not to use or alternatives, but the sibling tools list implies it's for a specific format.

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