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

Annotations only give readOnlyHint=false, openWorldHint=true, destructiveHint=false. The description adds substantial context beyond that: the default Draft state, that notify_client fires the New Invoice notification, that it 'Reaches other people' and requires per-call user confirmation, and the API key scope needed. These are exactly the side-effect and auth details an agent needs before a mutating, externally visible call.

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?

It is front-loaded with the creation statement and stays on topic, but it is a dense run-on paragraph with redundancy ('Saved as Draft unless you open and send it' and 'With status draft nothing is sent' restate each other) and an awkward leading fragment. Information is present but not tightly organized.

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 and light annotations, the description covers safety profile, side effects, confirmation behavior, and auth scope, so an agent can call it correctly. It stops short of explaining anything about the created invoice's identifier or follow-up, which is a minor gap given no output schema exists.

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 baseline is 3, but the description adds real meaning beyond the schema strings: the total = quantity x rate, status=draft sends nothing vs status=open lets the client pay, and notify_client triggers the New Invoice notification. This clarifies the practical effect of the enum and boolean flags rather than restating their labels.

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 names a specific verb+resource ('Creates an invoice for one client from items set up in Office, with a due date'), so the agent knows exactly what is produced and from what source. It does not explicitly differentiate from siblings like suitedash_get_invoice or suitedash_record_payment, but the create semantics are unambiguous.

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 clearly explains the draft-vs-open choice ('With status draft nothing is sent. With status open the client can pay it'), which guides how to call it, but it never names an alternative tool or states when to prefer a different tool over this one. Usage guidance is implied through status semantics rather than explicit routing.

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