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

With no annotations, the description carries the burden of behavioral disclosure. It adds useful behavior context: French wording, traditional hyphenation, and non-statutory status. However, it does not describe rounding, error handling, or how the amount is supplied, and the payment sentence is unrelated to tool behavior.

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 compact and front-loaded with the core purpose. Most sentences are useful, but 'Paid $0.01 USDC Base x402' is irrelevant to tool selection or invocation and should be removed for tighter structure.

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 no-parameter, no-output-schema formatter, the description provides enough orientation: purpose, domain, language, hyphenation style, and a legal caveat. It could be more precise about the expected input or return container, but the example largely compensates.

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?

There are no declared parameters and schema coverage is effectively 100%, so there is no parameter detail the description must compensate for. The parenthetical example illustrates the output but does not need to document parameters that do not exist.

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 that the tool converts amounts into French words for invoices and provides a concrete example ('douze euros et quarante centimes'). The additional phrase 'Not a statutory mention' helps distinguish it from legal/reference sibling tools.

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 scopes usage to invoice amounts and explicitly says the output is not a statutory mention, which helps an agent avoid misusing it as a legal clause. It does not name specific alternative tools, but the sibling list and the explicit exclusion make the intended context clear.

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