nex_mail_plan_list

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

The readOnlyHint annotation already establishes that this is a safe read operation. The description adds useful data-level context—the numeric-hour-to-enum mapping and the note that both mailbox types share prices—but does not describe return shape, pagination, or what 'enabled' means.

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?

The description is two short sentences with no wasted words. The primary action is front-loaded, and the follow-up sentence supplies only the mapping and sharing detail needed to interpret the listed prices.

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 tool, the description covers the source table and a key output mapping. However, with no output schema, it does not explain the full return structure—such as which fields appear per price record—leaving some interpretive work to the agent.

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 input parameters, so the baseline is 4. The description's mapping of numeric hours to purchase enums is relevant to interpreting the tool's output, even though it does not correspond to any input parameter.

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 and resource: 'List enabled mailbox prices from NEX_MAIL_PRICE.' It clearly distinguishes a read/list operation from the purchase operation implied by sibling nex_mail_buy, though it does not explicitly name that sibling.

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?

The description gives no explicit when-to-use guidance, no prerequisites, and no mention of alternatives such as nex_mail_buy. The implied use case (checking prices before purchase) is inferable but not stated.

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