send_text_message

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

There are no annotations, so the description carries the full burden. It states the primary side effect ('Send ... message') but does not disclose prerequisites like an active session, delivery behavior, failure modes, or any limits, which matter for a tool with a required 'session' parameter.

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 a single front-loaded sentence with no filler. Every phrase ('WhatsApp text message', 'contact, group, or channel') adds operational 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?

For a simple 3-parameter tool with full schema coverage, the description plus schema is mostly sufficient to invoke the tool. However, the absence of any behavioral context (e.g., needing an active session, or that media should use send_image/send_file) leaves minor gaps.

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 100%, so the input schema already documents text, chatId, and session sufficiently. The description adds no parameter-level meaning, but it does not need to compensate because the schema descriptions are clear.

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 uses a specific verb ('Send') and resource ('WhatsApp text message'), and explicitly lists target types ('contact, group, or channel'). This clearly distinguishes it from sibling tools like send_image and send_file based on message type.

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 implies usage for text messages and identifies recipient categories, but it does not explicitly state when not to use this tool or point to send_image/send_file for media. No prerequisites, such as needing an active session, are mentioned.

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