draft_invoice

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explains that the tool produces an invoice (not a cover email or reminder), outputs Markdown, and includes a professional header, line items, subtotal, optional tax, and total. It does not mention any destructive actions or side effects, which is appropriate for a document generation tool. A minor gap is the lack of explicit statement about whether it modifies any records, but the context implies it is a pure generation 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?

The description is approximately 6 sentences, each conveying essential information without redundancy. It is front-loaded with the primary action, specifies the output format, distinguishes from siblings, and summarizes required/optional parameters. No fluff – every sentence earns its place.

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 the tool's complexity (11 parameters, nested array for line_items) and lack of output schema, the description is remarkably complete. It explains the output format (Markdown) and content (header, line items, subtotal, tax, total). It also covers usage context and parameter guidelines. No gaps are apparent.

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 description coverage is 100%, so the baseline is 3. However, the description adds significant value beyond the schema: it explains the purpose of each optional parameter (e.g., 'Omit to leave a placeholder' for invoice_number, 'Omit for fixed-fee items' for quantity/rate), provides examples for date formats, and clarifies the line_items structure. This makes parameter semantics very clear.

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 it generates a complete, ready-to-send professional invoice document in Markdown format, and distinguishes itself from three sibling tools (invoice_cover_email, invoice_reminder, payment_plan_proposal). The verb 'Generate' and resource 'invoice document' are specific and unambiguous.

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 provides context for when to use the tool ('Ideal for converting an accepted proposal into a billable document') and lists required and optional parameters. It explicitly distinguishes from sibling tools, though it does not explicitly state when not to use it (e.g., avoid for sending reminders). Still, the guidance is clear and helpful.

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