Number (HLR) lookup

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

Annotations indicate non-read-only (readOnlyHint=false) and non-destructive (destructiveHint=false), but description adds valuable context: deducts balance, queues asynchronously, confirms accepted count, and requires scope. This goes beyond annotations, though it omits details like retries, error handling, or quota 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?

Three concise sentences, each adding distinct information: cost, action, asynchronous nature, response confirmation, and scope requirement. No redundancy or fluff.

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 explains async behavior and response confirmation but lacks details on response format, error scenarios, or what HLR provides. Without an output schema, more description of return values 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 100%, with both parameters (numbers, scheduled_at) described. The description adds only that lookups are 'batched' and response confirms accepted count, which is minimal extra meaning. Baseline 3 is appropriate.

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 it 'queues a batch of HLR number lookups' and deducts from wallet. The verb 'queues' and resource 'HLR number lookups' are specific and distinct from sibling tools, which include SMS, voice, USSD, and email operations.

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 mentions deducting wallet balance and requiring the 'lookup' scope, implying usage when you need number verification and have sufficient funds/permissions. However, it does not explicitly state when to use this tool versus alternatives (though no direct alternatives exist among siblings), nor provide when-not-to-use guidance.

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