nex_mail_domain_list

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

readOnlyHint=true already covers the safety profile, so little is owed. The description adds the useful downstream behavior that a returned domainId can be supplied or omitted for auto-assignment, but gives no sense of what each list entry contains or how many domains exist.

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 short sentences, front-loaded with the purpose and followed by the one actionable usage note. No filler.

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?

With no params, no output schema and an annotation covering safety, the definition is nearly complete for a simple list call. A brief note on what a returned domain entry looks like would close the remaining 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?

This tool takes zero parameters, so the schema baseline is 4. The description correctly adds no param details and instead clarifies how the returned domainId is consumed elsewhere, which is the only relevant semantic here.

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 and resource ('List available temporary mailbox domains'), which is clearly distinct from siblings like nex_mail_plan_list or nex_mail_record_list. It does not explicitly name a sibling it should not be confused with, so it stops short of a 5.

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 phrase 'Use a returned domainId or omit it for automatic assignment' implies the tool feeds a downstream purchase/creation call, but it never names that tool (e.g. nex_mail_buy) or states prerequisites. Usage is implied rather than explicit.

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