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

Annotations already establish read-only/non-destructive safety, and the description adds real behavioral context: results come newest-first, pages hold up to 100 invoices, and each item carries balance due and days overdue so callers need no second request. It also states the Cotlet API key/access requirement. This is meaningful added context beyond the annotations.

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?

Dense but front-loaded: it leads with what is returned, then status semantics, then pagination and auth. Every sentence contributes, though it is slightly long and the status glossary could be tighter.

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?

With no output schema, the description compensates by listing returned fields (customer, dates, total, balance due, days overdue), sort order, pagination size, available status filters, and the auth requirement. An agent has enough to call it correctly, though return value structure is described prose-only.

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 the baseline is 3, and the description genuinely adds semantics: it defines open=unpaid, closed=paid, credit=negative sale, and overdue=open past due date, which the bare enum labels do not convey. It also notes the 100-item page size associated with limit/cursor.

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 (list) and resource (MYOB sales invoices) plus the fields returned and the filtering dimension (status). It is unambiguous what the tool does, though it never explicitly contrasts itself with the sibling myob_get_invoice, so full sibling differentiation is missing.

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?

It explains what the status values mean and that overdue corresponds to the MYOB UI list, which implies usage, but it gives no explicit when-to-use versus myob_get_invoice or other siblings and no exclusions or prerequisites beyond an auth note.

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