Email payment receipt

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

Annotations already declare destructiveHint=true, openWorldHint=true and idempotentHint=false, so the 'Irreversible' sentence largely restates structured data. 'Real recipients' does add that external email is actually dispatched, but there is no mention of who the mail comes from, whether attachments default on, or rate/recipient-count limits despite maxItems=20.

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 short, front-loaded sentences with no filler. The only questionable element is the vague 'real recipients' qualifier, which is terse but under-explained rather than 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?

An eight-parameter, irreversible outbound-email mutation with no output schema needs more than a one-line summary: which payment/invoice pair is required, whether a PDF attachment is included by default, and what happens on failure are all absent. As written an agent knows the gist but not enough to invoke it confidently.

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 only 38%; five of eight parameters (message, subject, ccMyself, attachPdf, fromAddress) have no schema description at all. The tool description says nothing about any parameter, so it fails to compensate for the coverage gap on a fairly rich parameter set.

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 ('Email a receipt for an invoice payment'), which is distinguishable from wave_send_invoice and wave_send_estimate_deposit_receipt by the resource named. It does not explicitly contrast with those siblings, so it stops short of a 5.

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?

'Irreversible' implies a use-with-caution condition, but there is no explicit when-to-use versus wave_send_invoice or wave_get_invoice_payment, and no prerequisites such as requiring a recorded payment first. The phrase 'real recipients' gestures at a test-vs-production distinction without explaining it.

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