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

Annotations declare the write/open-world/non-idempotent profile, and the description adds genuinely new behavior: a new template is created as PENDING and is unusable until APPROVED via an external Meta review. That lifecycle and the delay it implies are not derivable from annotations or schema.

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?

Three tight sentences, front-loaded with the action and destination, then the approval constraint, then placeholder syntax. Every sentence carries distinct information with no 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?

For a 6-parameter creation tool with a fully documented schema and no output schema, the description covers the approval lifecycle, placeholder rules, and the follow-up tool for checking status. Return shape is unspecified but no output schema exists to anchor it, making this a minor gap.

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 baseline is 3, but the description adds ordering semantics for placeholders ('{{1}}, {{2}} in the body, in order') and notes they are filled at broadcast send time — detail the schema's bodyText description does not convey.

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?

States a specific verb+resource+destination: 'Submit a WhatsApp message template to Meta for approval.' This clearly separates it from list_whatsapp_templates, delete_whatsapp_template, and the unrelated flow tools among the many siblings.

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?

Explains the condition that makes templates necessary ('WhatsApp requires to write to someone outside the 24h window') and points to list_whatsapp_templates for status. It does not explicitly compare against adjacent creation tools like create_whatsapp_flow or create_reply_template, so it stops short of full when/when-not routing.

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