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

No annotations are provided, so the description carries the transparency burden. It fully discloses the routing logic including location-based phone numbers, which is the core behavioral trait. However, it doesn't clarify the return format (e.g., a URL string) or that no message is actually sent, which would be useful additional context.

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, front-loaded with the action and outcome. Every sentence adds value: the first defines the tool, the second provides routing details and usage guidance. No wasted words.

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?

Given the tool's moderate complexity (routing logic) and lack of output schema, the description covers the essential business rules well. However, it omits the return value structure (e.g., deep link URL) and the fact that all parameters are optional, leaving minor gaps for agent decision-making.

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 75%, so baseline is 3. The description reinforces the location parameter's routing impact, but the schema already covers this. It adds no extra meaning for message, customer_name, or product_context beyond schema descriptions, so it doesn't exceed 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 uses a specific verb ('Generate') and resource ('pre-filled WhatsApp deep link'), clearly stating the tool's function. It distinguishes itself from siblings like checkout or enquiry tools by focusing on WhatsApp handoff, which is absent in all sibling tools.

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?

Explicitly states when to use: 'when the customer prefers human assistance or when self-serve checkout isn't appropriate'. This gives clear context, though it doesn't name alternative tools or specify when not to use, which would make it a 5.

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