send_invoice

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states the action ('send an invoice via email') but lacks critical details: it doesn't mention authentication requirements, rate limits, whether the invoice status changes after sending, error handling, or what 'Response from the send invoice request' entails. This is inadequate for a mutation tool with zero annotation coverage.

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 well-structured with a brief purpose statement followed by parameter explanations and a returns section. It's front-loaded and efficient, though the 'Returns' line is vague and could be more informative, slightly reducing conciseness.

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 (6 parameters, mutation action) and lack of annotations/output schema, the description is partially complete. It excels in parameter semantics but falls short in behavioral transparency and usage guidelines, leaving gaps in understanding how and when to use the tool effectively.

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 description adds significant value beyond the input schema, which has 0% schema description coverage. It provides clear explanations for all 6 parameters, including optional behaviors (e.g., 'By default the email address of the client is used if it is set'), default logic, and purpose. This fully compensates for the schema's lack of descriptions.

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's purpose as 'Send an invoice via email,' which is a specific verb+resource combination. It distinguishes itself from sibling tools like 'send_invoice_overdue_reminder' by focusing on general invoice sending rather than reminders, though it doesn't explicitly contrast with other email-related 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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., invoice must exist), compare with other tools like 'send_invoice_overdue_reminder,' or specify scenarios where it's appropriate, leaving usage context unclear.

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