wa_send_template_message

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

With no annotations provided, the description adds key behavioral context: the message must be pre-approved and there is no 24-hour restriction. However, it does not disclose other important behaviors such as error conditions, fallback handling, or what happens if the template is invalid.

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 extremely concise, consisting of one sentence and a focused example for a single parameter. Every word adds value with no unnecessary 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?

This tool has six parameters, no schema descriptions, no annotations, and no output schema. The description covers only one parameter and the basic purpose, leaving substantial gaps around required fields like template_name and language_code, as well as expected return values and possible failure modes.

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 description coverage is 0%, yet the description only explains the 'components' parameter with an example. The parameters 'to', 'confirm', 'language_code', 'template_name', and 'phone_number_id' are not described, leaving the agent to guess their meaning. This is insufficient given the low schema coverage.

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 states a specific verb ('Send'), a clear resource ('pre-approved template message'), and the parenthetical '(works any time, no 24h window)' distinguishes it from regular messaging tools. This makes its purpose unambiguous and distinct from siblings like wa_send_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 explicitly notes that this tool works without the 24-hour window, which is a clear indication of when to use it. It does not name alternatives directly, but the context strongly implies it is for template messages when a standard message cannot be sent.

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