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

Annotations indicate a mutating tool (readOnlyHint=false) but provide no further behavioral details. The description does not explain what happens when creating an invoice with no parameters—e.g., whether it creates a blank draft, uses context, or errors out.

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 a single, concise phrase. It is to the point, though it could benefit from a brief usage note.

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?

With no parameters and no output schema, the description should clarify the tool's behavior (e.g., what invoice is created). It lacks completeness for a tool that presumably requires some implicit input.

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 input schema has zero parameters and 100% coverage, so the description does not need to add parameter info. However, the absence of parameters is unusual for a create tool, and no explanation is given.

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 'Créer une facture' clearly translates to 'Create an invoice', specifying the verb and resource. However, it does not distinguish this tool from the sibling 'invoice_from_quote', which also creates an invoice but from a quote.

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?

No guidance is provided on when to use this tool versus alternatives like 'invoice_from_quote'. The description lacks context about prerequisites or typical usage scenarios.

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