post--v3-sms-send

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

With no annotations, the description carries the full behavioral transparency burden. 'Send SMS' names the action, but it does not disclose side effects such as possible charges, dispatch behavior, invalid-recipient handling, or what the response will contain. There is no contradiction with annotations, but there is barely any behavioral context.

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 phrase is genuinely brief and front-loads the key verb, but it is more under-specified than usefully concise. A good summary would still be short, could include the target/manual alternatives for a fuller picture.

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?

This tool has a complex one-parameter schema containing an array of message objects with many nested constraints, and there is no output schema or annotations. A two-word description does not provide enough surrounding context for an agent to confidently choose and invoke this tool without potentially digging into every schema detail.

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 100%, so the JSON schema already documents the messages array and its nested properties in substantial detail. The description adds no parameter-level meaning beyond the word 'SMS', so the baseline score of 3 is appropriate.

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 states a concrete verb and resource: 'Send SMS' is clearly the outbound-SMS operation, distinct from sibling tools about pricing, history, statistics, or templates. It is short but not vague; a 5 would need more detail about recipients and message 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?

There is no explanation of when to use this tool versus alternatives such as post--v3-sms-price, nor any mention of preconditions like the need for a Sender ID or a recipient/list. The only guidance is the imperative 'Send SMS', so an agent must infer the intended usage context.

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