WhatsApp MCP for macOS

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

Annotations indicate readOnlyHint=false and destructiveHint=false, confirming this is a write operation but not destructive. The description adds valuable context beyond annotations: it requires WhatsApp connectivity (via whatsapp_status), needs a JID from another tool, and mandates user confirmation. No contradiction with annotations exists.

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 well-structured and front-loaded: the core purpose is stated first, followed by a clear IMPORTANT section with bullet points, then parameter explanations. Every sentence earns its place with no wasted words.

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 the tool has an output schema (which handles return values), annotations covering safety, and the description providing thorough usage guidelines and parameter semantics, this is complete for a messaging tool. It addresses prerequisites, user confirmation, and parameter sourcing effectively.

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?

With 0% schema description coverage, the description compensates by explaining both parameters: recipient_jid is 'The JID from whatsapp_search_contacts' and message is 'The text message to send.' This adds essential meaning beyond the bare schema, though it could specify JID format or message length limits.

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 the specific action ('Send a WhatsApp message') and resource ('WhatsApp'), distinguishing it from siblings like whatsapp_get_messages (retrieval) or whatsapp_status (connection check). The verb 'send' is precise and unambiguous.

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 explicitly provides when-to-use guidance in the IMPORTANT section: first use whatsapp_status to ensure connectivity, then use whatsapp_search_contacts to get the JID, and always confirm with the user. It names specific alternative tools (whatsapp_status, whatsapp_search_contacts) for prerequisites.

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