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

No annotations exist, so the description carries the full burden. It does disclose one real behavioral trait (no line items, details copied from the linked invoice), but says nothing about numbering side effects, whether creation is irreversible, or permission requirements. The schema's auto-increment/default notes compensate partially, leaving a moderate gap.

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?

Two tight sentences with the resource definition front-loaded and the most distinguishing constraint (no line items) placed second and emphasized. Nothing is wasted.

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 an 11-parameter creation tool with no annotations and no output schema, the pairing of a clear description and fully documented schema is nearly sufficient. Minor gap: no statement of what the call returns (e.g., generated document ID or series counter), which an agent creating then referencing the receipt would want.

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 all 11 parameters are already documented, including the invoice_id copy behavior and series/date defaults. The description adds no syntax or format detail beyond the schema; baseline 3 applies.

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 specific verb and resource ('Create a receipt') and immediately draws the key distinction from sibling document tools: 'A receipt has NO line items — it records a single amount, optionally linked to an invoice it pays.' An agent can separate create_receipt from create_invoice/create_payment on substance, not just name.

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 phrase 'optionally linked to an invoice it pays' implies the use case (recording a payment against an invoice) but never explicitly says when to choose this over create_payment or create_invoice, nor any prerequisites. Usage is inferable rather than stated.

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