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

With no annotations, the description must carry the full behavioral burden. It discloses mutation intent and the exactly-one-link constraint, but omits permissions, duplicate handling, reversibility, and response/error behavior for a create operation.

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?

Three sentences, front-loaded with purpose, then the linking constraint, then the amount workflow. There is no filler, and each sentence adds actionable information.

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 essential linking constraint and amount guidance for a 9-parameter mutation, but with no annotations or output schema it leaves out post-create behavior, failure modes, and permission expectations. Adequate but not fully complete.

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 would be 3. The description adds value beyond the schema by stating the exactly-one-of relationship among the four link IDs and explaining how to handle full settlement amounts.

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 ('Record') and resource ('payment'), and enumerates the four document types the payment can link to. It clearly distinguishes the create action from search/update/delete siblings, though it does not explicitly contrast with create_receipt.

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?

Specifies the key cross-field rule that exactly one of invoice_id, proforma_invoice_id, order_id, or supplier_invoice_id must be supplied. It also gives the full-payment workflow of reading outstanding balance first via get_invoice, but does not explicitly discuss when to choose update_payment or create_receipt.

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