send_message

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

No annotations are provided, so the description must disclose behavioral traits. It only states the action without mentioning side effects, prerequisites (e.g., contact existence), delivery guarantees, or rate limits. This leaves agents without critical 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 description is concise with two well-structured sentences and an Args section. Every part serves a purpose with no redundant or unnecessary 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 simple tool with two parameters, the description covers essential parameter semantics and purpose. However, it omits return values (no output schema) and lacks behavioral transparency, making it somewhat incomplete. More details on what happens after sending would improve completeness.

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?

The schema coverage is 0%, but the description adds significant value: it explains the target format (phone number with country code, no '+') and provides an example. For 'text,' it clarifies it is the message content, though somewhat minimally.

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 clearly states 'Send a WhatsApp text message to a contact,' providing a specific verb and resource. It naturally distinguishes from sibling tools like send_file, send_template, and send_interactive by specifying 'text message.'

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 implicitly defines usage for sending text messages, but it does not explicitly state when not to use it or list alternatives. However, the context is clear enough to avoid confusion with other message types.

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