create_device

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

With no annotations, the description carries the burden and it does disclose a key side effect: 'Costs the package price from your balance.' That is valuable beyond the schema. But it does not describe failure modes (e.g., insufficient balance), whether the operation is reversible, or what the response contains; no annotation contradiction exists.

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 short sentences, each earning its place: the action, the cost consequence, and the parameter source. The critical cost warning is front-loaded, and there is 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 two-parameter tool with complete schema documentation, the description covers the main prerequisite and the most important side effect. It lacks response/failure expectations and sibling differentiation, but the agent has enough to select and invoke the 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?

Schema coverage is 100%, and the schema already documents package_id as 'Package to buy. See list_packages.' The description repeats that source and mentions balance cost, but it does not add new parameter semantics such as format, constraints, or voucher_code behavior beyond the schema.

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 action and resource: 'Create a new WhatsApp device.' It is clearly distinct from messaging and status tools, and the economic consequence (package purchase) adds scope. However, it does not explicitly distinguish itself from sibling connect_device/renew_device, which could also relate to device lifecycle.

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?

It gives a useful prerequisite ('Get package_id from list_packages') and implies the create-via-package workflow, but it does not state when to choose this over connect_device, renew_device, or list_devices, nor any conditions/exclusions such as minimum balance requirements.

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