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

Adds substantial behavioral context beyond the annotations: the irreversibility of approval (only voidable), the draft's editability, that numbering comes from Invoicing preferences, and that each call requires user confirmation plus an API key with app access. These are exactly the traits an agent needs before firing a mutating call.

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?

Front-loaded with the core action and the highest-risk fact (approval is irreversible). Mostly tight, but the confirmation requirement is stated twice ('By default you confirm each call...' and 'confirm with the user before each call'), which is mild redundancy.

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?

Covers the mutation semantics, auth requirements, and confirmation policy for a 6-parameter tool with no output schema. The only gap is that no output schema exists and the description does not say what the created invoice returns (e.g., its ID), which an agent may need for follow-up calls.

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%, so baseline is 3, but the description adds real meaning: the approve flag's downstream consequences on editability, due_date being a single date, tax values keyed by account tax names, and line-item composition. Slightly above baseline.

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?

States a precise verb and resource ('Create a sales invoice') and immediately scopes the two modes of operation (draft vs approved). This distinguishes it from sibling tools like holded_create_purchase and holded_send_invoice without needing to name them.

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?

Gives explicit conditional guidance for the approve parameter: false (default) yields an editable draft, true yields an approved invoice that cannot be edited or deleted. It does not, however, name sibling alternatives or when to prefer them (e.g., holded_send_invoice for delivery).

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