list_send_as

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

No annotations are provided, so the description carries the transparency burden. It discloses that this is a read-only GET operation, which is helpful, but it does not mention authentication requirements, pagination, rate limits, or the response shape. Adequate for a trivial list call, but not rich.

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 dense sentences: the first defines the action and endpoint, the second scopes usage against alternatives. There is no filler or redundant restatement of the tool name.

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 zero-parameter read-only list operation with no output schema, the description is mostly complete: it names the endpoint and gives selection guidance. It does not describe the return value shape, which would have been helpful given the absence of an output schema, but the operation's simplicity keeps the gap small.

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?

The tool has zero parameters and an empty input schema, so the description does not need to explain parameter meanings. Per the baseline for zero-parameter tools, the endpoint and listing scope provide enough context.

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 uses a specific verb ('List'), a specific resource ('Gmail sendAs aliases'), and the exact API endpoint (GET users.me.settings.sendAs), making the tool's purpose unmistakable. It also implicitly differentiates itself from the sibling get_attachment and from stock Gmail MCP by scoping the plugin to sendAs and attachment work.

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 clear guidance: 'Use this plugin only for sendAs + attachment bytes' and explicitly says to use 'stock Gmail MCP for inbox search, labels, and triage.' This names an alternative for other tasks, though it does not explicitly distinguish list_send_as from the closely named sibling send_as.

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