Send bulk WhatsApp messages

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

Annotations already indicate write operation (readOnlyHint false) and side effects (openWorldHint true). Description adds specific behavioral warning about high impact and need for confirmation, which goes beyond annotations.

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 sentences: first states core function with key constraints (max 500, connected session), second provides a critical usage warning. No extraneous information.

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?

Given complexity (4 parameters, no output schema), the description covers the main purpose, recipient limit, and prerequisites. Missing details on return value or error conditions, but adequate for a bulk send 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?

Input schema covers 100% of parameters with descriptions. The tool description does not add any additional parameter-level meaning beyond what the schema already provides, so a 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?

Description clearly states 'Send the same WhatsApp message to many recipients (max 500)', specifying verb (send), resource (WhatsApp message), and scope (many recipients, max 500). It distinguishes from sibling 'send_whatsapp' which targets a single recipient.

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?

Description provides context: 'High-impact: this contacts many people. Confirm the recipient list before calling.' It implies careful usage but does not explicitly contrast with alternatives like 'send_whatsapp'.

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