receipts_email

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

Annotations already cover the side-effect profile (readOnly=false, idempotent=false, openWorld=true), and the description adds meaningful context: the PDF attachment is included, subject/body are auto-generated when omitted, and non-client addresses fail with the named error EMAIL_RECIPIENT_NOT_CLIENT. It stops short of saying what is returned on success (e.g., delivery record).

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 short sentences, front-loaded with the action and the recipient constraint; nothing is padded and the error case is stated compactly at the end.

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 an 8-parameter, output-schema-less mutation tool, the description covers the action, customization scope, and the failure mode that would otherwise waste a call. It could go further on prerequisites (e.g., receipt must be issued) and on what a successful send produces.

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 schema already explains all 8 parameters including the auto-defaults. The description's mention of subject, body, CC, and BCC adds little beyond the schema and stays silent on companyId and templateId selection.

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 (send), resource (receipt / bon fiscal), and delivery channel (email, PDF attached), which cleanly separates it from receipts_pdf and receipts_email_history in the sibling list.

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 gives a real precondition ('recipients must be client emails registered on the company'), but never says when to prefer this over receipts_pdf, receipts_email_defaults, or invoices_email, nor what to do if the receipt is unissued or unsubmitted.

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