validate_einvoice

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

With no annotations, the description carries full burden. It discloses the validation behavior, return value structure, and authentication requirement. It does not mention side effects, rate limits, or cost, but for a read-only validation tool this is acceptable.

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 three sentences with no wasted words. It front-loads the core validation action and output, then usage guidance, then authentication. Every sentence adds value.

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?

Given no output schema, the description adequately explains returns. All parameters are documented, and authentication is covered. It lacks detail on error handling or response format specifics, but overall sufficient for a validation tool.

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 coverage is 100% with good descriptions. The main description adds overall purpose but does not significantly enhance parameter meaning beyond the schema descriptions. The API key is mentioned as an external requirement.

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 validates EU electronic invoices against multiple official standards, and lists what it returns (validity and violation details). However, it could better distinguish from sibling tool explain_error_code, which likely serves a complementary role.

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?

It explicitly says to use before shipping or transmitting invoices to catch rejections early, and notes the required API key. It does not discuss when not to use or explicitly compare to sibling tools.

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