nex_sms_code_get

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

Annotations only declare readOnlyHint=true, so the description carries most of the burden and does it well: it discloses the polling loop and its termination conditions, and that SMS lacking a valid timestamp are silently dropped. It does not mention timeout/empty-result behavior or failure modes, but the behavioral picture for a read tool is solid.

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?

Front-loaded with the core action, then parameter semantics, then the sibling hand-off — a logical order with no filler. It is dense but every clause carries information; only the parenthetical '(max 120)' mildly duplicates the schema's maximum constraint.

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?

No output schema exists, yet the opening sentence signals the return content (latest SMS plus its code), and the filtering flags explain what will and will not appear in that result. Missing are the shape of the returned code/SMS and what happens on timeout with no code, but it is close to sufficient for a four-parameter read tool.

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 must supply all meaning, and it covers the three non-obvious parameters: waitSeconds (max 120, poll until code or stop), onlyNew (snapshot-at-first-pull semantics), and receivedAfter (ISO time in the sender's timezone, time-less SMS excluded). 'tel' is left implicit but is self-evident as the purchased number.

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 first sentence gives a specific verb and resource with scope: 'Read the latest SMS and code of one purchased number.' That is unambiguous about what comes back. It does not, however, differentiate itself from nex_sms_record_list, which is the other obvious sibling for SMS data, so the agent must guess which one to pick when it only wants a list.

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 concrete usage conditions: waitSeconds polls until a code arrives or the number stops waiting; receivedAfter ignores earlier SMS; onlyNew ignores codes already present at the first pull. It also routes the agent to nex_sms_code_fill for actually typing the code into a page. What is missing is any statement of when to prefer this over nex_sms_record_list.

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