Learn how to use the WhatsApp tools

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

The description adds 'never touches WhatsApp' and 'takes no arguments,' which reinforce and extend the annotations (readOnlyHint=true, destructiveHint=false, idempotentHint=true). The 'never touches WhatsApp' claim is a meaningful behavioral assurance beyond the abstract readOnly hint — it tells the agent this is safe with zero side effects. Consistent with all annotations, no contradiction.

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, zero waste, and the most critical usage instruction ('Read this FIRST') is front-loaded in the first clause. The second sentence packs the full content scope efficiently. For a zero-parameter reference tool, this is the ideal length.

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?

Complete for a zero-parameter documentation tool. It covers when to use it (first, before anything else), what it delivers (tools guide, id formats, workflows, message shape, error codes with remediation), and side effects (none). The absence of an output schema is immaterial since the tool's output is itself the guide it returns, which is described in sufficient detail.

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 zero parameters, the baseline is 4 per the rubric. The description confirms 'takes no arguments,' which matches the empty input schema. Nothing further is needed for parameter semantics since there are no parameters to document.

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 purpose: returning a guide covering tool usage, id formats, workflows, message shape, and error codes. This clearly distinguishes it from the 21 action-oriented sibling tools (send_message, delete_message, etc.), none of which are documentation tools. The verb 'Returns' plus the concrete content list make the purpose unmistakable.

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 opening sentence — 'Read this FIRST, before any other WhatsApp tool' — gives explicit, unambiguous usage ordering. It tells the agent exactly when to invoke this tool relative to all siblings. No alternatives are named because none exist; this is the only documentation tool among the set.

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