textverified_create_rental

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

With no annotations, the description carries full behavioral burden. It discloses that this is a purchase and that explicit confirmation is required, but omits cost implications, whether the rental is reversible, permission requirements, and what confirmation entails beyond the boolean parameter.

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 description is a single front-loaded sentence with no fluff, so it is efficient and readable. However, it is arguably under-sized for a 9-parameter mutation tool, which keeps it from being a model of appropriately scaled conciseness.

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?

An output schema exists, so return values need not be explained, but the definition still leaves major gaps. With no annotations, 9 undocumented parameters, and only a terse confirmation note, an agent lacks the context needed to call this purchase tool correctly.

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?

The schema has 0% description coverage across 9 parameters, and the description adds no meaning for any of them. There is only an implicit nod to confirm_purchase, with no explanation of service_name, duration, options, capability, number_type, is_renewable, idempotency_key, or allow_back_order_reservations.

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 a specific verb and resource: 'Purchase a rental number.' This distinguishes it from siblings focused on SMS, calls, verifications, and settings. It does not explicitly name an alternative or boundary, so it falls short of a 5.

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 only usage signal is 'requires explicit confirmation,' which is a precondition rather than guidance on when to choose this tool over alternatives like create_verification or send_sms. No when-to-use or when-not-to-use context is provided.

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