bach-whatsapp_number_validators

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

With no annotations provided, the description carries full behavioral disclosure burden. It successfully reveals the specific behavior of suggesting alternative country-specific numbers for invalid inputs, but omits other critical operational details like authentication requirements, rate limits, or error handling behaviors.

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?

The two-sentence structure is reasonably efficient, though the opening 'You can utilize' is filler that doesn't add value. The second sentence provides specific behavioral details that earn its place, but the description could be more direct about the input mechanism.

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 empty input schema and lack of output schema, the description fails to adequately explain how to invoke the tool (missing parameter documentation) or provide complete return value documentation beyond the alternative-number behavior. The mismatch between described functionality and empty schema is a critical 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?

Although the schema has 0 parameters (baseline 4), the description confusingly refers to 'a given number' and verifying 'the validity of a given number', implying input parameters exist that are not reflected in the schema. This creates ambiguity about how the phone number is actually provided to the tool.

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 the tool validates phone numbers and provides alternative valid numbers for different countries when invalid. However, it fails to distinguish from siblings like 'phone_number_validation_via_get_request' or 'validate_single_number_via_post_request', leaving ambiguity about when to choose this specific variant.

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?

No guidance is provided on when to use this tool versus alternatives (e.g., POST vs GET variants, single vs bulk validation). The description lacks prerequisites, input requirements, or exclusion criteria despite having multiple similar sibling tools.

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