Send WhatsApp message

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

Annotations already indicate a mutable action (readOnlyHint=false, openWorldHint=true). The description adds the prerequisite of an existing session but does not disclose rate limits, error conditions, or side effects beyond sending.

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, no wasted words. The first sentence states the main action, the second adds the critical prerequisite and cross-reference. Front-loaded and efficient.

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 send tool with four parameters and no output schema, the description covers the core purpose and prerequisite. It lacks mention of error handling or return value, but is adequate overall.

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?

The input schema covers all four parameters with descriptions, achieving 100% coverage. The tool description does not significantly add meaning beyond the schema, so score is at the baseline.

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 tool sends a WhatsApp message to one recipient from a connected session, using specific verb and resource. It distinguishes from siblings like send_bulk_whatsapp by emphasizing single recipient and references list_whatsapp_sessions for prerequisites.

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?

It provides clear context: requires a session_id from an already-paired session and links to list_whatsapp_sessions. However, it does not explicitly state when not to use this tool or mention alternatives for bulk sending.

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