nex_sms_record_list

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

With readOnlyHint=true already declaring the safety profile, the description adds real value by disclosing the returned fields, especially that the latest verification code is included rather than requiring a separate nex_sms_code_get call. Pagination behavior for page/size is not described, which is the only notable gap.

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?

Three short sentences in a deliberate order: what it returns, when to call it, then the one non-obvious parameter. No filler and no 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 read-only list tool with no output schema, the description covers the essentials: what is returned, when to use it, and the key filter. Pagination behavior and the exact shape of each record are the remaining gaps, but they are minor for a tool whose primary value is 'is a number already owned'.

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 description coverage is 0%, so the description carries the burden and only partially meets it: it explains that keyword matches by number or project, which is genuinely useful beyond the 'string' type. The page and size parameters receive no explanation at all, leaving two of three parameters undocumented anywhere.

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 purchased cloud phone numbers') and immediately names the payload that distinguishes it from siblings: state, expiry, and the latest verification code. An agent can tell this apart from nex_sms_buy or nex_sms_code_get without opening any schema.

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?

'Check here before asking for a phone number or offering a number purchase for a sign-up' gives an explicit trigger condition, effectively routing the agent away from nex_sms_buy when a number already exists. It stops short of naming the excluded alternative or stating what to do when the list comes back empty.

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