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

Goes well beyond the annotations (readOnlyHint=false, destructiveHint=false, openWorldHint=true) by disclosing that an over-amount creates a debit note, that the response returns amount applied per bill with the new balance, that each call is confirmed by default (switchable), that it reaches other people so the user must be consulted, and that a Cotlet API key with app access is required. This is exactly the kind of side-effect, auth, and approval context the description should carry.

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?

Purpose is front-loaded in the first sentence, followed by behavior, side effects, and prerequisites in a tight sequence. Six sentences, each carrying distinct information, with no filler.

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 a mutation tool with no output schema, the description supplies the return shape (amount applied and new balance per bill), the destructive/side-effect profile, the confirmation and human-in-the-loop requirement, and the credential prerequisite. Nothing an agent needs to invoke it safely is missing.

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 3 is the baseline, but the description adds genuine semantics: the amount parameter's over-payment behavior (debit note creation) and the bank-account source of funds. The send_remittance and bill-ordering guidance largely repeats the schema, capping the score at 4.

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 ('Record a payment to a supplier against one or more open bills') and scopes it to supplier bills, which implicitly separates it from the sibling myob_record_invoice_payment (customer-side). An agent can identify the operation without opening the schema.

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 clear context for when this tool applies (paying a supplier against open bills from a bank account) and clarifies it does not select Electronic payment, so no money leaves MYOB. It does not explicitly name an alternative sibling or state exclusions, so it falls short of the 5 bar.

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