ncloud_mailer_get_address_book

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

Beyond the readOnlyHint annotation, the description discloses deprecation status, migration deadline, the endpoint, and a key limitation ('There is no API to list the individual addresses of a group'). This gives the agent essential behavioral expectations and prevents false assumptions.

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?

Compact and front-loaded with the most critical legacy constraint before the action. Every clause earns its place, with no filler or redundancies.

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 read-only tool with one optional parameter and no output schema, the description supplies the endpoint, return structure, and a significant missing capability. Nothing an agent needs to correctly decide or invoke this tool is absent.

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%: the region parameter already documents its enum values, path-segment semantics, and defaulting behavior. The description adds no further parameter detail beyond referencing the endpoint.

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+resource, 'Get the address book summary (GET /address-book),' and names the concrete return fields (totalAddressCount and per-group sid/groupName/addressCount. The legacy/SENS framing distinguishes it from mail-sending siblings, and the limitation about no individual-address listing further sharpens the scope.

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?

Explicitly scopes availability: only for projects migrated from Cloud Outbound Mailer and only until ~Dec 2027, naming ncloud_sens_send_mail and ncloud_sens_list_mail_requests as successors. It does not explicitly contrast with sibling address-book create/delete tools, but those operations are clearly distinct.

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