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

No annotations are provided, so the description carries the full behavioral burden. It mentions that a free OTP key sends from the WALoops WhatsApp number and that the channel may be whatsapp or sms, but it omits important side effects, delivery behavior, rate limits, permission requirements, and failure modes for an external send operation.

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 concise sentences with the core action front-loaded. There is no redundant or wasted text.

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 tool with four parameters, no annotations, and no output schema, the description is thin. It covers the basic action and channel behavior but omits the verification workflow, expected response behavior, and other operational details an agent would need to use it confidently.

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 75%, so most parameters are already documented. The description adds that the phone number should be international and clarifies channel values, but it does not add much beyond the schema, particularly for purpose or site_url.

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: sending an OTP to an international phone number. It clearly distinguishes this from the sibling verify_otp tool by focusing on sending rather than verifying.

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 implies this is the tool for initiating OTP delivery and notes channel options, but it gives no explicit when-to-use guidance, no mention of when not to use it, and no direct routing to verify_otp as the natural next step.

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