Create send-as alias

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

No annotations are provided, so the description carries the full behavioral burden. The parenthetical about domain/verification rules is a genuine constraint, but the description says nothing about required scopes/permissions, whether the alias needs separate verification, or what a failed creation means. For a mutation tool with zero annotation coverage, this is thin.

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?

A single front-loaded sentence with no wasted words, and the qualifier is placed where it belongs. It is efficient, though arguably too terse to be useful.

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 4-parameter mutation tool with 50% schema coverage, no annotations, and no output schema, the description leaves the agent guessing about half the inputs and the entire behavioral profile. The one parenthetical does not close the gap.

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 50%: 'account' and 'sendAsEmail' are documented in the schema, while 'isDefault' and 'displayName' are undocumented in both schema and description. The description adds no parameter meaning (e.g., that sendAsEmail must be a verified address, or what isDefault implies), so it fails to compensate for the coverage gap.

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 states a specific verb and resource ('Create a Gmail send-as alias'), which an agent can distinguish from the read-only sibling google_gmail_sendas_list. It does not explicitly name or differentiate itself from siblings, but the verb+resource pairing is 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?

There is no guidance on when to use this versus google_gmail_sendas_list or other Gmail tools. The parenthetical '(subject to domain/verification rules)' hints at a precondition but never states it as a usage condition (e.g., what must be true before creating an alias).

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