send_message

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

No annotations are provided, so the description carries the full disclosure burden. It does disclose the return shape (a dictionary with success status and status message), but says nothing about side effects beyond the obvious send, authentication/connection requirements, rate limits, or what happens with an invalid recipient.

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 purpose is front-loaded in the first sentence, followed by the group-chat caveat and a compact Args/Returns block. Every line adds information and there is no filler.

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?

With only two required parameters and no output schema, the description covers the essentials of calling the tool and the return value. It is still thin on the operational context an unannotated write-style tool needs, such as authentication state and delivery/error outcomes.

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%, so the description must compensate, and it does: 'recipient' is documented with the phone-number format (country code, no + or symbols) and two concrete JID examples, including a group JID; 'message' is defined as the message text. The only gap is behavior on malformed input.

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?

States a specific verb and resource ('Send a WhatsApp message to a person or group'), which an agent can distinguish from send_audio_message and send_file by the message type. It does not explicitly name those siblings or draw the boundary, so it falls short of a 5.

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 line 'For group chats use the JID' gives a concrete condition for choosing the recipient format, which is real usage guidance. However, there is no guidance on when to prefer this over send_audio_message/send_file, no preconditions such as an authenticated session, and no failure handling.

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