Check Whatsapp

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

There are no annotations, so the description carries the full behavioral burden. It does not state whether the operation is read-only, whether it contacts the WhatsApp service, what the return value looks like, or any side effects. The description only names the check without explaining observable behavior.

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, no filler, and the main purpose is front-loaded. Every word adds value, and the description is appropriately sized for a simple one-parameter tool.

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 simple one-parameter check tool, the description conveys the core use but lacks expected phone formatting and return result semantics. Since there is no output schema, the agent is left to infer what the outcome of the check looks like. It is adequate but not complete.

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 coverage is 0% and the description does not explain the expected phone format (e.g., country code, digits, international format). It simply calls it a 'номер' (number), leaving important parameter semantics undocumented.

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 specific action: checking whether a phone number has WhatsApp. It effectively communicates the tool's core purpose and adds a practical context (check before first sending to a stranger), though it does not explicitly distinguish it from sibling tools.

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 gives clear when-to-use guidance: 'Проверяйте перед первой отправкой незнакомцу' (check before first sending to a stranger). It does not mention alternative tools or exclusion cases, but the intended context is clear.

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