wa_send_message

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

With no annotations, the description fully discloses the key behavioral aspects: passing through allowlist, secret scan, rate limit, and confirmation gates. It explains the conditional re-call pattern but omits details on error handling or specific rate limits.

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 with no filler. The first sentence states the core action, the second adds critical workflow detail. Every word contributes to understanding.

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?

The description adequately covers the main behavior but lacks details on the output schema's role (e.g., that it returns 'needs_confirm' and 'confirm_token'). It assumes knowledge of the security gate components without elaboration. For a tool with a confirmation workflow, more context would improve completeness.

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. It clarifies the 'confirm_token' parameter's role in the confirmation workflow. However, it does not specify the expected format for 'recipient' or any length constraints for 'message', leaving some ambiguity.

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 specific verb 'Send', the resource 'WhatsApp text message', and the constraint 'allowlisted recipient'. It effectively distinguishes from sibling tools like wa_send_file (sends files) and wa_preview (previews).

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 explains the security gate and the two-step confirmation workflow involving 'needs_confirm' and 'confirm_token'. It lacks explicit alternatives for when not to use this tool, but the context is sufficient for appropriate selection.

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